WorldWideScience

Sample records for bioreactors beeinflussung des

  1. Messsysteme zur Untersuchung einer möglichen Beeinflussung des Menschen durch elektromagnetische Felder

    OpenAIRE

    Waldmann, Jan

    2003-01-01

    Die vorliegende Arbeit beschäftigt sich mit der Entwicklung und Charakterisierung von Mess-systemen zur Bestimmung einer möglichen Beeinflussung des menschlichen Körpers durch elektromagnetische Felder. Exemplarisch werden anhand von drei Beispielen Messsysteme vorgestellt, mit deren Hilfe diese mögliche Beeinflussung untersucht werden kann. Dabei werden neben thermischen Wirkungen elektromagnetischer Wellen, also der Erwärmung des Gewebes auf Grund absorbierter Feldenergie, auch nicht-th...

  2. Beeinflussung der Propriozeption des oberen Sprunggelenkes durch Orthesen

    OpenAIRE

    Becker, Björn-Wiclif

    2006-01-01

    Ziel der vorliegenden Studie war die Untersuchung des Einflusses von Orthesen auf die neuromuskuläre Stabilisierung des oberen Sprunggelenks. Über ein alternatives Studiendesign wurden die mechanischen und neuromuskulären Eigenschaften einer Orthese getrennt und durch Auslösung des H-Reflexes an der Peroneusmuskulatur die Reflexschleife eines Dehnungsreflexes im Rahmen einer akuten Supination simuliert. Mittels EMG wurde das resultierende Reflex-Summenaktionspotential bei 20 Probanden erfasst...

  3. Bioreactor

    Science.gov (United States)

    1996-01-01

    The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues currently being cultured in rotating bioreactors by investigators

  4. Gegenseitige Beeinflussung von Mizellaren Strukturen und Photodimerisierung von Cumarinderivaten

    OpenAIRE

    Yu, Xiuling

    2004-01-01

    In dieser Arbeit wurde die gegenseitige Beeinflussung von mizellaren Strukturen und Photodimerisierung von Cumarinderivaten untersucht. Als Mizellbildner wurden das kationische Cetyltrimethylammoniumbromid (CTAB) und das nicht-ionische Triton X-100, als Solubilisate Cumarinderivaten verwendet. Es wurden rheologische, thermodynamische und photochemische Untersuchungen durchgeführt. Die Viskosität der beiden Tensidsysteme steigt mit zunehmender Solubilisatkonzentration je nach Cumarinderivat un...

  5. Perioperative Veränderungen der Sauerstoffsättigungskurve anhand des p50-Wertes sowie Beeinflussung über die Hämoglobin-bezogene 2,3-Diphosphoglycerat-Konzentration durch postoperative Gabe von Kaliumphosphat bei herzchirurgischen Patienten

    OpenAIRE

    Sehlleier, Simone

    2002-01-01

    Das Thema dieser Studie behandelt die perioperativen Veränderungen der Sauerstoffsättigungskurve bei herzchirurgischen Patienten, dargestellt anhand des p50-Wertes. Darüberhinaus wird versucht, durch postoperative Gabe von anorganischem Phosphat in Form von Kaliumphosphat den 2,3-DPG-Metabolismus zu stimulieren und somit den p50-Wert anzuheben. Im Mittelpunkt steht die 'Phosphat-Gruppe', deren Patienten postoperativ Kaliumphosphat erhalten haben. Die p50- und 2,3-DPG-Werte wurden mit den W...

  6. Bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Jamaleddine, E. [McGill Univ., Montreal, PQ (Canada). Dept. of Bioresource Engineering

    2010-07-01

    Composting is once again gaining interest among ecological engineers in view of greener industrial and residential activities. Uniform composting is needed to ensure decomposition and to keep the whole system at the same composting stage. A homogeneous temperature must be maintained throughout the media. A bioreactor design consisting of a heater core made of copper tubing was designed and tested. Two four-inch holes were made at the top and bottom of the barrel to allow air to flow through the system and promote aerobic composting. Once composting began and temperature increased, the water began to flow through the copper piping and the core heat was distributed throughout the medium. Three thermocouples were inserted at different heights on a 200 litre plastic barrel fitted with the aforementioned apparatus. Temperature variations were found to be considerably lower when the apparatus was operated with the heat redistribution system, enabling uniform composting, accelerating the process and reducing the risks of pathogenic or other contaminants remaining active in the barrels.

  7. Therapeutic management of radiation-induced oral mucositis; Therapeutische Beeinflussung der radiogenen oralen Mukositis

    Energy Technology Data Exchange (ETDEWEB)

    Doerr, W. [Klinik und Poliklinik fuer Strahlentherapie, Universitaetsklinikum Carl Gustav Carus, Technische Univ. Dresden (Germany); Doelling-Jochem, I. [Klinik und Poliklinik fuer Strahlentherapie, Universitaetsklinikum Carl Gustav Carus, Technische Univ. Dresden (Germany); Baumann, M. [Klinik und Poliklinik fuer Strahlentherapie, Universitaetsklinikum Carl Gustav Carus, Technische Univ. Dresden (Germany); Herrmann, T. [Klinik und Poliklinik fuer Strahlentherapie, Universitaetsklinikum Carl Gustav Carus, Technische Univ. Dresden (Germany)

    1997-04-01

    Proliferation von Tumorstammzellen, die in der Folge die Tumorheilungsaussichten drastisch verringern kann. Zudem fuehren ueberschiessende Akutreaktionen in vielen Faellen zu einer Verstaerkung von spaeten Strahlenfolgen. Die Verminderung der Schleimhautreaktion mit dem Ziel der Vermeidung von Bestrahlungspausen und der Verminderung von Spaetschaeden kann den therapeutischen Erfolg der Radiotherapie entscheidend verbessern. Verschiedene Ansaetze zur Beeinflussung der strahleninduzierten Mukositis auf symptomatischer oder strahlen- und epithelbiologischer Grundlage wurden zusammengefass und systematisch dargestellt. Es existiert eine Vielzahl prophylaktischer und therapeutischer Ansaetze zur Verminderung akuter radiogener Reaktionen der Mundschleimhaut. Haeufig ist die Wirksamkeit jedoch nur fuer Chemotherapie oder im Zusammenhang mit einer immunsuppressiven Therapie nachgewiesen, so dass oft eher ein systemischer als ein lokaler Effekt angenommen werden muss. Als allgemeine Mukositisprophylaxe koennen neben einer Zahnsanierung regelmaessige mundhygienische Massnahmen sowie antiseptische Spuelungen herangezogen werden. Die Bedeutung einer engmaschigen persoenlichen Betreuung der Patienten ist zu betonen. Das Anlegen eines perkutanen endoskopischen Gastrostoma muss am Zustand des Patienten sowie an der Ausdehnung und Lage des Bestrahlungsfeldes und damit der zu erwartenden Beeintraechtigung der Nahrungsaufnahme orientiert werden. Als therapeutische Massnahmen bei manifesten Schleimhautreaktionen kommen eine lokale bzw. systemische Schmerzbehandlung sowie die lokale Applikation von Antimykotika und Antibiotika in Betracht. (orig./VHE)

  8. MDMA ("Ecstasy") in Tiermodellen des Morbus Parkinson

    OpenAIRE

    Lebsanft, Heike Birgit

    2004-01-01

    Die gute symptomatische Anti-Parkinson-Wirkung von MDMA wurde in Tiermodellen bei der Ratte nachgewiesen. Die Derivate und Enantiomere von MDMA unterscheiden sich in ihrer Wirksamkeit. Im Rotationsverhalten sind die Substanzen effektiver, die stärker auf das dopaminerge System wirken, wie MDA oder das S(+)-Enantiomer von MDMA. Da die Beeinflussung das serotonergen Systems und des Opioid-Systems die gute Wirksamkeit von MDMA behinderte, sind diese Systeme am Wirkmechanismus beteiligt. Das sero...

  9. NASA Bioreactor

    Science.gov (United States)

    1996-01-01

    Close-up view of the interior of a NASA Bioreactor shows the plastic plumbing and valves (cylinders at center) to control fluid flow. A fresh nutrient bag is installed at top; a flattened waste bag behind it will fill as the nutrients are consumed during the course of operation. The drive chain and gears for the rotating wall vessel are visible at bottom center center. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  10. Bioreactor principles

    Science.gov (United States)

    2001-01-01

    Cells cultured on Earth (left) typically settle quickly on the bottom of culture vessels due to gravity. In microgravity (right), cells remain suspended and aggregate to form three-dimensional tissue. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  11. Treatment of sediments from soil washing plants. Investigation of the suitability of a gas/solids fluidized bed bioreactor for the decontamination; Bodenwaschanlagen-Sedimente behandeln. Untersuchungen der Eignung des Gas/Feststoff-Wirbelschicht-Bioreaktors zur Dekontaminierung

    Energy Technology Data Exchange (ETDEWEB)

    Behns, W.; Haida, H. [Magdeburg Univ. (Germany). Inst. fuer Apparate- und Umwelttechnik; Friedrich, C. [Allgaier-Werke, Uhingen (Germany)

    1997-09-01

    This article deals with the possibility of microbiological decontamination of sediments from soil washing plants in gas/solids fluidized bed bioreactors. The sediments are pressed to granulates. The pollutants which are removed are mineral oil hydrocarbons. The degradation results of this process are presented, the process seems to be an alternative to common waste treatment processes. (SR) [Deutsch] Die mikrobiologische Dekontaminierung sandiger Boeden in einem Gas/Feststoff-Wirbelschicht-Bioreaktor ist eine erfolgversprechende Alternative zu anderen biologischen Reinigungsverfahren. Die biologische Dekontaminierung von Schlufffraktionen oder von Bodenwaschanlagensedimenten (BWS) ist deutlich schwieriger. In der Literatur werden vor allem Verfahren unter Einsatz von Suspensionsreaktoren verwendet, um fuer Feinkorn-Fraktionen eine biologische Reinigung zu ermoeglichen. Hier soll ueber Untersuchungen berichtet werden, mit denen die Eignung des Gas/Feststoff-Wirbelschicht-Bioreaktors fuer die Dekontaminierung derartiger Boeden ueberprueft werden sollte. (orig.)

  12. NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    Bioreactor Demonstration System (BDS) comprises an electronics module, a gas supply module, and the incubator module housing the rotating wall vessel and its support systems. Nutrient media are pumped through an oxygenator and the culture vessel. The shell rotates at 0.5 rpm while the irner filter typically rotates at 11.5 rpm to produce a gentle flow that ensures removal of waste products as fresh media are infused. Periodically, some spent media are pumped into a waste bag and replaced by fresh media. When the waste bag is filled, an astronaut drains the waste bag and refills the supply bag through ports on the face of the incubator. Pinch valves and a perfusion pump ensure that no media are exposed to moving parts. An Experiment Control Computer controls the Bioreactor, records conditions, and alerts the crew when problems occur. The crew operates the system through a laptop computer displaying graphics designed for easy crew training and operation. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. See No. 0101825 for a version with major elements labeled, and No. 0103180 for an operational schematic. 0101816

  13. NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    Biotechnology Specimen Temperature Controller (BSTC) will cultivate cells until their turn in the bioreactor; it can also be used in culturing experiments that do not require the bioreactor. The BSTC comprises four incubation/refrigeration chambers individually set at 4 to 50 deg. C (near-freezing to above body temperature). Each chamber holds three rugged tissue chamber modules (12 total), clear Teflon bags holding 30 ml of growth media, all positioned by a metal frame. Every 7 to 21 days (depending on growth rates), an astronaut uses a shrouded syringe and the bags' needleless injection ports to transfer a few cells to a fresh media bag, and to introduce a fixative so that the cells may be studied after flight. The design also lets the crew sample the media to measure glucose, gas, and pH levels, and to inspect cells with a microscope. The controller is monitored by the flight crew through a 23-cm (9-inch) color computer display on the face of the BSTC. This view shows the BTSC with the front panel open. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  14. Bioreactor landfill

    Institute of Scientific and Technical Information of China (English)

    WANG Hao; XING Kai; Anthony Adzomani

    2004-01-01

    Following the population expansion, there is a growing threat brought by municipal solid waste (MSW) against environment and human health. Sanitary landfill is the most important method of MSW disposal in China. In contrast to the conventional landfill, this paper introduces a new technique named bioreactor landfill (BL). Mechanisms, operation conditions as well as the advantages and disadvantages of BL are also discussed in this paper.

  15. Use of gas/solid matter fluidized-bed bioreactors in microbiological soil cleanup; Nutzung des Gas/Feststoff-Wirbelschicht-Bioreaktors in der mikrobiologischen Bodensanierung

    Energy Technology Data Exchange (ETDEWEB)

    Behns, W.; Friedrich, K.; Haida, H. [Marburg Univ. (Germany). Inst. fuer Apparate- und Umwelttechnik

    1998-04-01

    The fluidization of contaminated soil with air in a gas/solid matter fluidized-bed bioreactor basically offers favourable preconditions for aerobic microbiological pollutant degradation, in the meaning of a kind of solid state fermentation. The technical principle, the pilot plant, and experimental investigations using a model system made up of soil, a pollutant (dibutyl-phthalate), and micro-organisms has already been reported on. This article presents results of experimental studies using soil substrates with real contaminations of mineral oil hydrocarbons (MHCs) or hexachloro-cyclohexane(HCH). In economic terms, the combination of treatment in a fluidized bed with subsequent treatment in a bed or pit has proved expedient. (orig.) [Deutsch] Wird schadstoffbelasteter Boden in einem Gas/Feststoff-Wirbelschicht-Bioreaktor mit Luft fluidisiert, bestehen prinzipiell gute Voraussetzungen fuer den aeroben mikrobiologischen Schadstoffabbau im Sinne einer Solid-State-Fermentation. Ueber das Verfahrensprinzip, die Versuchsanlage und experimentelle Untersuchungen an einem Modellsystem Boden - Schadstoff (Dibutylphthalat) - Mikroorganismen wurde bereits berichtet. Nachfolgend sollen Ergebnisse experimenteller Untersuchungen mit real kontaminierten Bodenmassen - Schadstoffe Mineraloelkohlenwasserstoffe (MKW) bzw. Hexachlorcyclohexan (HCH) - dargestellt werden. Aus oekonomischer Sicht hat sich die Kombination einer Behandlung in der Wirbelschicht und nachfolgend in einem Beet bzw. Eine Miete als guenstig erwiesen. (orig.)

  16. Bioreactors addressing diabetes mellitus.

    Science.gov (United States)

    Minteer, Danielle M; Gerlach, Jorg C; Marra, Kacey G

    2014-11-01

    The concept of bioreactors in biochemical engineering is a well-established process; however, the idea of applying bioreactor technology to biomedical and tissue engineering issues is relatively novel and has been rapidly accepted as a culture model. Tissue engineers have developed and adapted various types of bioreactors in which to culture many different cell types and therapies addressing several diseases, including diabetes mellitus types 1 and 2. With a rising world of bioreactor development and an ever increasing diagnosis rate of diabetes, this review aims to highlight bioreactor history and emerging bioreactor technologies used for diabetes-related cell culture and therapies.

  17. Bioreactors Addressing Diabetes Mellitus

    OpenAIRE

    Minteer, Danielle M.; Gerlach, Jorg C; Marra, Kacey G.

    2014-01-01

    The concept of bioreactors in biochemical engineering is a well-established process; however, the idea of applying bioreactor technology to biomedical and tissue engineering issues is relatively novel and has been rapidly accepted as a culture model. Tissue engineers have developed and adapted various types of bioreactors in which to culture many different cell types and therapies addressing several diseases, including diabetes mellitus types 1 and 2. With a rising world of bioreactor develop...

  18. NASA Bioreactor Demonstration System

    Science.gov (United States)

    2002-01-01

    Leland W. K. Chung (left), Director, Molecular Urology Therapeutics Program at the Winship Cancer Institute at Emory University, is principal investigator for the NASA bioreactor demonstration system (BDS-05). With him is Dr. Jun Shu, an assistant professor of Orthopedics Surgery from Kuming Medical University China. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Credit: Emory University.

  19. Bioreactor rotating wall vessel

    Science.gov (United States)

    2001-01-01

    The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Cell constructs grown in a rotating bioreactor on Earth (left) eventually become too large to stay suspended in the nutrient media. In the microgravity of orbit, the cells stay suspended. Rotation then is needed for gentle stirring to replenish the media around the cells.

  20. Tapered bed bioreactor

    Science.gov (United States)

    Scott, Charles D.; Hancher, Charles W.

    1977-01-01

    A vertically oriented conically shaped column is used as a fluidized bed bioreactor wherein biologically catalyzed reactions are conducted in a continuous manner. The column utilizes a packing material a support having attached thereto a biologically active catalytic material.

  1. Bioreactors and bioseparation.

    Science.gov (United States)

    Zhang, Siliang; Cao, Xuejun; Chu, Ju; Qian, Jiangchao; Zhuang, Yingping

    2010-01-01

    Along with the rapid development of life science, great attention has been increasingly given to the biotechnological products of cell cultivation technology. In the course of industrialization, bioreactor and bioproduct separation techniques are the two essential technical platforms. In this chapter, the current situation and development prospects of bioreactor techniques in China are systematically discussed, starting with the elucidation of bioreactor processes and the principle of process optimization. Separation technology for biological products is also briefly introduced.At present, a series of bioreactors made by Chinese enterprises have been widely used for laboratory microbial cultivation, process optimization studies, and large-scale production. In the course of bioprocess optimization studies, the complicated bioprocesses in a bioreactor could be resolved into different reaction processes on three scales, namely genetic, cellular, and bioreactor scales. The structural varieties and nonlinear features of various scales of bioprocess systems was discussed through considering the mutual effects of different scale events, namely material flux, energy flux, and information flux, and the optimization approach for bioprocesses was proposed by taking the analysis of metabolic flux and multiscale consideration as a core strategy.In order to realize such an optimization approach, a bioreactor system based on association analysis of multiscale parameters was elaborated, and process optimization of many biological products were materialized, which resulted in great improvement in production efficiency. In designing and manufacturing large-scale bioreactors, the principle of scaling up a process incorporated with flow field study and physiological features in a bioreactor was suggested according to the criterion for the scale-up of cellular physiological and metabolic traits. The flow field features of a bioreactor were investigated through computational fluid

  2. Bioreactors and bioseparation.

    Science.gov (United States)

    Zhang, Siliang; Cao, Xuejun; Chu, Ju; Qian, Jiangchao; Zhuang, Yingping

    2010-01-01

    Along with the rapid development of life science, great attention has been increasingly given to the biotechnological products of cell cultivation technology. In the course of industrialization, bioreactor and bioproduct separation techniques are the two essential technical platforms. In this chapter, the current situation and development prospects of bioreactor techniques in China are systematically discussed, starting with the elucidation of bioreactor processes and the principle of process optimization. Separation technology for biological products is also briefly introduced.At present, a series of bioreactors made by Chinese enterprises have been widely used for laboratory microbial cultivation, process optimization studies, and large-scale production. In the course of bioprocess optimization studies, the complicated bioprocesses in a bioreactor could be resolved into different reaction processes on three scales, namely genetic, cellular, and bioreactor scales. The structural varieties and nonlinear features of various scales of bioprocess systems was discussed through considering the mutual effects of different scale events, namely material flux, energy flux, and information flux, and the optimization approach for bioprocesses was proposed by taking the analysis of metabolic flux and multiscale consideration as a core strategy.In order to realize such an optimization approach, a bioreactor system based on association analysis of multiscale parameters was elaborated, and process optimization of many biological products were materialized, which resulted in great improvement in production efficiency. In designing and manufacturing large-scale bioreactors, the principle of scaling up a process incorporated with flow field study and physiological features in a bioreactor was suggested according to the criterion for the scale-up of cellular physiological and metabolic traits. The flow field features of a bioreactor were investigated through computational fluid

  3. NASA Bioreactor Schematic

    Science.gov (United States)

    2001-01-01

    The schematic depicts the major elements and flow patterns inside the NASA Bioreactor system. Waste and fresh medium are contained in plastic bags placed side-by-side so the waste bag fills as the fresh medium bag is depleted. The compliance vessel contains a bladder to accommodate pressure transients that might damage the system. A peristolic pump moves fluid by squeezing the plastic tubing, thus avoiding potential contamination. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  4. NASA Classroom Bioreactor

    Science.gov (United States)

    Scully, Robert

    2004-01-01

    Exploration of space provides a compelling need for cell-based research into the basic mechanisms that underlie the profound changes that occur in terrestrial life that is transitioned to low gravity environments. Toward that end, NASA developed a rotating bioreactor in which cells are cultured while continuously suspended in a cylinder in which the culture medium rotates with the cylinder. The randomization of the gravity vector accomplished by the continuous rotation, in a low shear environment, provides an analog of microgravity. Because cultures grown in bioreactors develop structures and functions that are much closer to those exhibited by native tissue than can be achieved with traditional culture methods, bioreactors have contributed substantially to advancing research in the fields of cancer, diabetes, infectious disease modeling for vaccine production, drug efficacy, and tissue engineering. NASA has developed a Classroom Bioreactor (CB) that is built from parts that are easily obtained and assembled, user-friendly and versatile. It can be easily used in simple school settings to examine the effect cultures of seeds or cells. An educational brief provides assembly instructions and lesson plans that describes activities in science, math and technology that explore free fall, microgravity, orbits, bioreactors, structure-function relationships and the scientific method.

  5. Die technische Beeinflussung des Verhaltens von Sauen am Beispiel der Aufruffütterung und einer aktiven Erdrückungsverhinderung

    OpenAIRE

    Manteuffel, Christian

    2015-01-01

    Under intensive husbandry conditions, the natural behaviour repertoire of livestock is often contrary to an optimal productivity and also animal welfare. This problem can be reduced by technically manipulating the animal behaviour in terms of precision livestock farming, so that husbandry conditions and animal behaviour adjust mutually to one another. The current work exemplifies this approach for appetitive stimulations at the example of call feeding gestating sows and for aversive stimulati...

  6. Hämodynamische Beeinflussung des hyperdynamischen septischen Schocks im Großtiermodel - Noradrenalin und ein selektiver V1a-Agonist

    OpenAIRE

    Klotz, Matthias

    2011-01-01

    Introduction: Septic shock is one of the most common diseases on intensive care units. The recent Surviving Sepsis Campaign international guidelines for management of septic shock suggest norepinephrine or dopamine as first line vasopressor and vasopressin as an alternative. Vasopressin is an effective vasoactive drug due to activating the V1a- receptor. Disadvantages of vasopressin like antidiuresis, hypercoagulation and selective vasodilatation are mediated by the V2- receptor. Material and...

  7. Cascades of bioreactors.

    NARCIS (Netherlands)

    Gooijer, de C.D.

    1995-01-01

    In this thesis a common phenomenon in bioprocess engineering is described : the execution of a certain bioprocess in more than one bioreactor. Chapter 1, a review, classifies bioprocesses by means of a number of characteristics :i) processes with a variable stoichiometry ,ii) processes with a consta

  8. NASA Bioreactor tissue culture

    Science.gov (United States)

    1998-01-01

    Dr. Lisa E. Freed of the Massachusetts Institute of Technology and her colleagues have reported that initially disc-like specimens tend to become spherical in space, demonstrating that tissues can grow and differentiate into distinct structures in microgravity. The Mir Increment 3 (Sept. 16, 1996 - Jan. 22, 1997) samples were smaller, more spherical, and mechanically weaker than Earth-grown control samples. These results demonstrate the feasibility of microgravity tissue engineering and may have implications for long human space voyages and for treating musculoskeletal disorders on earth. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  9. Basic bioreactor design.

    NARCIS (Netherlands)

    Riet, van 't K.; Tramper, J.

    1991-01-01

    Based on a graduate course in biochemical engineering, provides the basic knowledge needed for the efficient design of bioreactors and the relevant principles and data for practical process engineering, with an emphasis on enzyme reactors and aerated reactors for microorganisms. Includes exercises.

  10. Membrane bioreactor for waste gas treatment.

    OpenAIRE

    Reij, M W

    1997-01-01

    SummaryThis thesis describes the design and testing of a membrane bioreactor (MBR) for removal of organic pollutants from air. In such a bioreactor for biological gas treatment pollutants are degraded by micro-organisms. The membrane bioreactor is an alternative to other types of bioreactors for waste gas treatment, such as compost biofilters and bioscrubbers. Propene was used as a model pollutant to study the membrane bioreactor.A membrane bioreactor for waste gas treatment consists of a gas...

  11. Oscillating Cell Culture Bioreactor

    Science.gov (United States)

    Freed, Lisa E.; Cheng, Mingyu; Moretti, Matteo G.

    2010-01-01

    To better exploit the principles of gas transport and mass transport during the processes of cell seeding of 3D scaffolds and in vitro culture of 3D tissue engineered constructs, the oscillatory cell culture bioreactor provides a flow of cell suspensions and culture media directly through a porous 3D scaffold (during cell seeding) and a 3D construct (during subsequent cultivation) within a highly gas-permeable closed-loop tube. This design is simple, modular, and flexible, and its component parts are easy to assemble and operate, and are inexpensive. Chamber volume can be very low, but can be easily scaled up. This innovation is well suited to work with different biological specimens, particularly with cells having high oxygen requirements and/or shear sensitivity, and different scaffold structures and dimensions. The closed-loop changer is highly gas permeable to allow efficient gas exchange during the cell seeding/culturing process. A porous scaffold, which may be seeded with cells, is fixed by means of a scaffold holder to the chamber wall with scaffold/construct orientation with respect to the chamber determined by the geometry of the scaffold holder. A fluid, with/without biological specimens, is added to the chamber such that all, or most, of the air is displaced (i.e., with or without an enclosed air bubble). Motion is applied to the chamber within a controlled environment (e.g., oscillatory motion within a humidified 37 C incubator). Movement of the chamber induces relative motion of the scaffold/construct with respect to the fluid. In case the fluid is a cell suspension, cells will come into contact with the scaffold and eventually adhere to it. Alternatively, cells can be seeded on scaffolds by gel entrapment prior to bioreactor cultivation. Subsequently, the oscillatory cell culture bioreactor will provide efficient gas exchange (i.e., of oxygen and carbon dioxide, as required for viability of metabolically active cells) and controlled levels of fluid

  12. Design challenges for space bioreactors

    Science.gov (United States)

    Seshan, P. K.; Petersen, G. R.

    1989-01-01

    The design of bioreactors for operation under conditions of microgravity presents problems and challenges. Absence of a significant body force such as gravity can have profound consequences for interfacial phenomena. Marangoni convection can no longer be overlooked. Many speculations on the advantages and benefits of microgravity can be found in the literature. Initial bioreactor research considerations for space applications had little regard for the suitability of the designs for conditions of microgravity. Bioreactors can be classified in terms of their function and type of operation. The complex interaction of parameters leading to optimal design and operation of a bioreactor is illustrated by the JSC mammalian cell culture system. The design of a bioreactor is strongly dependent upon its intended use as a production unit for cell mass and/or biologicals or as a research reactor for the study of cell growth and function. Therefore a variety of bioreactor configurations are presented in rapid summary. Following this, a rationale is presented for not attempting to derive key design parameters such as the oxygen transfer coefficient from ground-based data. A set of themes/objectives for flight experiments to develop the expertise for design of space bioreactors is then proposed for discussion. These experiments, carried out systematically, will provide a database from which engineering tools for space bioreactor design will be derived.

  13. Study of metabolic pathways for hydrogen production in chlamydomonas reinhardtii and transposition on a torus photo bioreactor; Etude des voies metaboliques de production d'hydrogene chez la microalgue Chlamydomonas reinhardtii et transposition en photobioreacteur

    Energy Technology Data Exchange (ETDEWEB)

    Fouchard, S

    2006-04-15

    Considering the recent increase in energy consumption. aide associated environmental risks, new trails are followed today to develop the use of clean and renewable alternative energies. In this context hydrogen seems to be a serious solution and this study, based on micro-algae photosynthetic capacities exploitation, will allow to devise a process for hydrogen production from only water and solar energy without greenhouse gas release. The sulphur deprivation protocol on TAP medium, known to lead to hydrogen production in Chlamydomonas reinhardtii species was particularly studied. At the metabolic level, two important phenomena are induced under these conditions: an over-accumulation of the intracellular starch reserves and a simultaneous alteration of the PsII activity which leads to anoxia and Fe-hydrogenase induction, an enzyme with a strong specific activity responsible for the hydrogen production. The contribution of the two electron transfer pathways implied in the hydrogen production process (PsII-dependent and PSII-independent) as well as the importance of the previously accumulated starch were highlighted here. We also investigated the potential for designing autotrophic protocols for hydrogen photoproduction. Various protocols, considered to be relevant, were then transposed on a torus photo-bioreactor, specifically developed in this study and which allows the control of culture parameters as well as the precise measurement of gas release kinetics, in order to obtain first estimates of productivity of the system. Integration of the physical; aspects of the pilot and biological aspects of the process in a model, finally opens new prospects for subject development, in particular for a reasoned optimization of hydrogen production via this double physiology/process approach. (author)

  14. Sensing in tissue bioreactors

    Science.gov (United States)

    Rolfe, P.

    2006-03-01

    Specialized sensing and measurement instruments are under development to aid the controlled culture of cells in bioreactors for the fabrication of biological tissues. Precisely defined physical and chemical conditions are needed for the correct culture of the many cell-tissue types now being studied, including chondrocytes (cartilage), vascular endothelial cells and smooth muscle cells (blood vessels), fibroblasts, hepatocytes (liver) and receptor neurones. Cell and tissue culture processes are dynamic and therefore, optimal control requires monitoring of the key process variables. Chemical and physical sensing is approached in this paper with the aim of enabling automatic optimal control, based on classical cell growth models, to be achieved. Non-invasive sensing is performed via the bioreactor wall, invasive sensing with probes placed inside the cell culture chamber and indirect monitoring using analysis within a shunt or a sampling chamber. Electroanalytical and photonics-based systems are described. Chemical sensing for gases, ions, metabolites, certain hormones and proteins, is under development. Spectroscopic analysis of the culture medium is used for measurement of glucose and for proteins that are markers of cell biosynthetic behaviour. Optical interrogation of cells and tissues is also investigated for structural analysis based on scatter.

  15. Cells growing in NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    For 5 days on the STS-70 mission, a bioreactor cultivated human colon cancer cells, which grew to 30 times the volume of control specimens grown on Earth. This significant result was reproduced on STS-85 which grew mature structures that more closely match what are found in tumors in humans. Shown here, clusters of cells slowly spin inside a bioreactor. On Earth, the cells continually fall through the buffer medium and never hit bottom. In space, they are naturally suspended. Rotation ensures gentle stirring so waste is removed and fresh nutrient and oxygen are supplied. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  16. Analyse des besoins des usagers

    OpenAIRE

    KHOUDOUR,L; LANGLAIS,A; Charpentier, C.; MOTTE,C; PIAN,C

    2002-01-01

    Il s'agit d'étendre la surveillance vidéo de l'enceinte du métro vers l'intérieur des rames. Les images captées constituent des prises de vue des événements qui se déroulent à l'intérieur des véhicules afin notamment d'améliorer la sécurité des usagers transportes. Il est possible de mémoriser les images des quelques instants précédant un incident usager, d'analyser ces images en temps différé et de mieux appréhender en temps réel le comportement des usagers face à des événements ou des consi...

  17. Latinismen des Italienischen in DELI und LEI

    Directory of Open Access Journals (Sweden)

    Gerhard Ernst

    1991-12-01

    Full Text Available Als "Latinismen" sollen im folgenden diejenigen Wörter verstanden werden, deren Existenz, Form oder Bedeutung in einer der romanischen Sprachen auf Lehnbeziehungen während der lateinischen Diglossie oder auf die weiterbestehenden kulturellen Kontakte zum Lateinischen zurückgehen. Die Spendersprache bzw. beeinflussende Sprache kann dabei das Latein der Vergangenheit sein – insbesondere der Zeit, in der von romanischen Sprachen noch keine Rede sein konnte -, aber auch dasjenige, das neben den romanischen Sprachen als Mittellatein, Humanistenlatein, Kirchenlatein, Gelehrtenlatein weiterexistierte. Trotz verschiedener Terminologien ("gelehrte Wörter", "Buchwörter", "voci dotte", "mots savants", "cultismos" bestehen in der Abgrenzung dieses Teilbereichs des Lexikons der romanischen Sprachen keine gravierenden Unterschiede in neuerer einschlägiger Literatur. Allerdings laßt sich zwischen solchen Latinismen unterscheiden, die als sprachliches Zeichen (mit Form und Bedeutung aus dem Latein in die jeweilige romanische Sprache übernommen wurden (mehr oder weniger an das jeweilige Sprachsystem adaptiert, und solchen, die - bei ununterbrochener Überlieferung - nur eine Beeinflussung durch ein entsprechendes lateinisches Wort erfuhren ("voci semidotte", "rriots demi-sevants", "semicultismos". "El latín, en este caso, no presta términos, sino que ayuda - únicamente - a mantener fonemas y morfemas: siglo, virgen" (Alvar/Mariner 1967, 6. Alvar/Mariner (1967, 7 haben daneben auch eine weitere Untergruppe der "semicultismos": Latinismen, die phonetisch adaptiert wurden; wie respeto, afición. Diese beiden Typen von "semicultismos" verhalten sich ihrem Ursprung nach komplementär: a Erbwörter mit Beibehaltung lautlicher Elemente (evtl. auch der Bedeutung durch den Kontakt mit dem Lateinischen3 ; b Latinismen mit starker volkssprachlicher Adaptierung.

  18. Spiral vane bioreactor

    Science.gov (United States)

    Morrison, Dennis R. (Inventor)

    1991-01-01

    A spiral vane bioreactor of a perfusion type is described in which a vertical chamber, intended for use in a microgravity condition, has a central rotating filter assembly and has flexible membranes disposed to rotate annularly about the filter assembly. The flexible members have end portions disposed angularly with respect to one another. A fluid replenishment medium is input from a closed loop liquid system to a completely liquid filled chamber containing microcarrier beads, cells and a fluid medium. Output of spent medium is to the closed loop. In the closed loop, the output and input parameters are sensed by sensors. A manifold permits recharging of the nutrients and pH adjustment. Oxygen is supplied and carbon dioxide and bubbles are removed and the system is monitored and controlled by a microprocessor.

  19. Controlled-Turbulence Bioreactors

    Science.gov (United States)

    Wolf, David A.; Schwartz, Ray; Trinh, Tinh

    1989-01-01

    Two versions of bioreactor vessel provide steady supplies of oxygen and nutrients with little turbulence. Suspends cells in environment needed for sustenance and growth, while inflicting less damage from agitation and bubbling than do propeller-stirred reactors. Gentle environments in new reactors well suited to delicate mammalian cells. One reactor kept human kidney cells alive for as long as 11 days. Cells grow on carrier beads suspended in liquid culture medium that fills cylindrical housing. Rotating vanes - inside vessel but outside filter - gently circulates nutrient medium. Vessel stationary; magnetic clutch drives filter cylinder and vanes. Another reactor creates even less turbulence. Oxygen-permeable tubing wrapped around rod extending along central axis. Small external pump feeds oxygen to tubing through rotary coupling, and oxygen diffuses into liquid medium.

  20. Bioreactor Mass Transport Studies

    Science.gov (United States)

    Kleis, Stanley J.; Begley, Cynthia M.

    1997-01-01

    The objectives of the proposed research efforts were to develop both a simulation tool and a series of experiments to provide a quantitative assessment of mass transport in the NASA rotating wall perfused vessel (RWPV) bioreactor to be flown on EDU#2. This effort consisted of a literature review of bioreactor mass transport studies, the extension of an existing scalar transport computer simulation to include production and utilization of the scalar, and the evaluation of experimental techniques for determining mass transport in these vessels. Since mass transport at the cell surface is determined primarily by the relative motion of the cell assemblage and the surrounding fluid, a detailed assessment of the relative motion was conducted. Results of the simulations of the motion of spheres in the RWPV under microgravity conditions are compared with flight data from EDU#1 flown on STS-70. The mass transport across the cell membrane depends upon the environment, the cell type, and the biological state of the cell. Results from a literature review of cell requirements of several scalars are presented. As a first approximation, a model with a uniform spatial distribution of utilization or production was developed and results from these simulations are presented. There were two candidate processes considered for the experimental mass transport evaluations. The first was to measure the dissolution rate of solid or gel beads. The second was to measure the induced fluorescence of beads as a stimulant (for example hydrogen peroxide) is infused into the vessel. Either technique would use video taped images of the process for recording the quantitative results. Results of preliminary tests of these techniques are discussed.

  1. Progress in bioreactors of bioartiifcial livers

    Institute of Scientific and Technical Information of China (English)

    Cheng-Bo Yu; Xiao-Ping Pan; Lan-Juan Li

    2009-01-01

    BACKGROUND: Bioartiifcial liver support systems are becoming an effective therapy for hepatic failure. Bioreactors, as key devices in these systems, can provide a favorable growth and metabolic environment, mass exchange, and immunological isolation as a platform. Currently, stagnancy in bioreactor research is the main factor restricting the development of bioartiifcial liver support systems. DATA SOURCES: A PubMed database search of English-language literature was performed to identify relevant articles using the keywords "bioreactor", "bioartiifcial liver", "hepatocyte", and "liver failure". More than 40 articles related to the bioreactors of bioartiifcial livers were reviewed. RESULTS: Some progress has been made in the improvement of structures, functions, and modiifed macromolecular materials related to bioreactors in recent years. The current data on the improvement of bioreactor conifgurations for bioartiifcial livers or on the potential of the use of certain scaffold materials in bioreactors, combined with the clinical efifcacy and safety evaluation of cultured hepatocytesin vitro, indicate that the AMC (Academic Medical Center) BAL bioreactor and MELS (modular extracorporeal liver support) BAL bioreactor system can partly replace the synthetic and metabolic functions of the liver in phaseⅠ clinical studies. In addition, it has been indicated that the microlfuidic PDMS (polydimethylsiloxane) bioreactor, or SlideBioreactor, and the microfabricated grooved bioreactor are appropriate for hepatocyte culture, which is also promising for bioartiifcial livers. Similarly, modiifed scaffolds can promote the adhesion, growth, and function of hepatocytes, and provide reliable materials for bioreactors.CONCLUSIONS: Bioreactors, as key devices in bioartiifcial livers, play an important role in the therapy for liver failure both now and in the future. Bioreactor conifgurations are indispensable for the development of bioartiifcial livers used for liver

  2. Preliminary Study on Airlift Membran—Bioreactor

    Institute of Scientific and Technical Information of China (English)

    XUNong; XINGWeihong; 等

    2002-01-01

    A new type of membrane bioreactor named “airlift membrane-bioreactor”is discussed.For municipal wastewater reclamation,the preliminary study on airlift membrane-bioreactor shows its good performance such as high flux and lower energy consumption.The airlift membrane-bioreactor is potentially applicable in bioengineering and environmental protection fields.

  3. Tissue grown in NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    Cells from kidneys lose some of their special features in conventional culture but form spheres replete with specialized cell microvilli (hair) and synthesize hormones that may be clinically useful. Ground-based research studies have demonstrated that both normal and neoplastic cells and tissues recreate many of the characteristics in the NASA bioreactor that they display in vivo. Proximal kidney tubule cells that normally have rich apically oriented microvilli with intercellular clefts in the kidney do not form any of these structures in conventional two-dimensional monolayer culture. However, when normal proximal renal tubule cells are cultured in three-dimensions in the bioreactor, both the microvilli and the intercellular clefts form. This is important because, when the morphology is recreated, the function is more likely also to be rejuvenated. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC).

  4. Bioreactor technology for herbal plants

    International Nuclear Information System (INIS)

    Plants have been an important source of medicine for thousands of years and herbs are hot currency in the world today. During the last decade, popularity of alternative medicine increased significantly worldwide with noticeable trend. This in turn accelerated the global trade of herbal raw materials and herbal products and created greater scope for Asian countries that possess the major supply of herbal raw materials within their highly diversified tropical rain forest. As such, advanced bioreactor culture system possesses a great potential for large scale production than the traditional tissue culture system. Bioreactor cultures have many advantages over conventional cultures. Plant cells in bioreactors can grow fast and vigorously in shorter period as the culture conditions in bioreactor such as temperature, pH, concentrations of dissolved oxygen, carbon dioxide and nutrients can be optimised by on-line manipulation. Nutrient uptake can also be enhanced by continuous medium circulation, which ultimately increased cell proliferation rate. Consequently, production period and cost are substantially reduced, product quality is controlled and standardized as well as free of pesticide contamination and production of raw material can be conducted all year round. Taking all these into consideration, current research efforts were focused on varying several parameters such as inoculation density, air flow, medium formulation, PGRs etc. for increased production of cell and organ cultures of high market demand herbal and medicinal plants, particularly Eurycoma longifolia, Panax ginseng and Labisia pumila. At present, the production of cell and organ culture of these medicinal plants have also been applied in airlift bioreactor with different working volumes. It is hope that the investment of research efforts into this advanced bioreactor technology will open up a bright future for the modernization of agriculture and commercialisation of natural product. (author)

  5. Following an Optimal Batch Bioreactor Operations Model

    DEFF Research Database (Denmark)

    Ibarra-Junquera, V.; Jørgensen, Sten Bay; Virgen-Ortíz, J.J.;

    2012-01-01

    The problem of following an optimal batch operation model for a bioreactor in the presence of uncertainties is studied. The optimal batch bioreactor operation model (OBBOM) refers to the bioreactor trajectory for nominal cultivation to be optimal. A multiple-variable dynamic optimization of fed...... as the master system which includes the optimal cultivation trajectory for the feed flow rate and the substrate concentration. The “real” bioreactor, the one with unknown dynamics and perturbations, is considered as the slave system. Finally, the controller is designed such that the real bioreactor...

  6. Use Alkalinity Monitoring to Optimize Bioreactor Performance.

    Science.gov (United States)

    Jones, Christopher S; Kult, Keegan J

    2016-05-01

    In recent years, the agricultural community has reduced flow of nitrogen from farmed landscapes to stream networks through the use of woodchip denitrification bioreactors. Although deployment of this practice is becoming more common to treat high-nitrate water from agricultural drainage pipes, information about bioreactor management strategies is sparse. This study focuses on the use of water monitoring, and especially the use of alkalinity monitoring, in five Iowa woodchip bioreactors to provide insights into and to help manage bioreactor chemistry in ways that will produce desirable outcomes. Results reported here for the five bioreactors show average annual nitrate load reductions between 50 and 80%, which is acceptable according to established practice standards. Alkalinity data, however, imply that nitrous oxide formation may have regularly occurred in at least three of the bioreactors that are considered to be closed systems. Nitrous oxide measurements of influent and effluent water provide evidence that alkalinity may be an important indicator of bioreactor performance. Bioreactor chemistry can be managed by manipulation of water throughput in ways that produce adequate nitrate removal while preventing undesirable side effects. We conclude that (i) water should be retained for longer periods of time in bioreactors where nitrous oxide formation is indicated, (ii) measuring only nitrate and sulfate concentrations is insufficient for proper bioreactor operation, and (iii) alkalinity monitoring should be implemented into protocols for bioreactor management.

  7. Two new disposable bioreactors for plant cell culture: The wave and undertow bioreactor and the slug bubble bioreactor.

    Science.gov (United States)

    Terrier, Bénédicte; Courtois, Didier; Hénault, Nicolas; Cuvier, Arnaud; Bastin, Maryse; Aknin, Aziz; Dubreuil, Julien; Pétiard, Vincent

    2007-04-01

    The present article describes two novel flexible plastic-based disposable bioreactors. The first one, the WU bioreactor, is based on the principle of a wave and undertow mechanism that provides agitation while offering convenient mixing and aeration to the plant cell culture contained within the bioreactor. The second one is a high aspect ratio bubble column bioreactor, where agitation and aeration are achieved through the intermittent generation of large diameter bubbles, "Taylor-like" or "slug bubbles" (SB bioreactor). It allows an easy volume increase from a few liters to larger volumes up to several hundred liters with the use of multiple units. The cultivation of tobacco and soya cells producing isoflavones is described up to 70 and 100 L working volume for the SB bioreactor and WU bioreactor, respectively. The bioreactors being disposable and pre-sterilized before use, cleaning, sterilization, and maintenance operations are strongly reduced or eliminated. Both bioreactors represent efficient and low cost cell culture systems, applicable to various cell cultures at small and medium scale, complementary to traditional stainless-steel bioreactors.

  8. Filtration characteristics in membrane bioreactors

    NARCIS (Netherlands)

    Evenblij, H.

    2006-01-01

    Causes of and remedies for membrane fouling in Membrane Bioreactors for wastewater treatment are only poorly understood and described in scientific literature. A Filtration Characterisation Installation and a measurement protocol were developed with the aim of a) unequivocally determination and quan

  9. PRACTICE REVIEW OF FIVE BIOREACTOR/RECIRCULATION LANDFILLS

    Science.gov (United States)

    Six bioreactor landfills were analyzed to provide a perspective of current practice and technical issues that differentiate bioreactor landfills from conventional landfills. Five of the bioreactor landfills were anaerobic and one was aerated. In one case, nearly identical cells e...

  10. Bioreactor design and optimization – a future perspective

    DEFF Research Database (Denmark)

    Gernaey, Krist

    2011-01-01

    Bioreactor design and optimisation are essential in translating the experience gained from lab or pilot scale experiments to efficient production processes in industrial scale bioreactors. This article gives a future perspective on bioreactor design and optimisation, where it is foreseen that tec......Bioreactor design and optimisation are essential in translating the experience gained from lab or pilot scale experiments to efficient production processes in industrial scale bioreactors. This article gives a future perspective on bioreactor design and optimisation, where it is foreseen...

  11. Prostate tumor grown in NASA Bioreactor

    Science.gov (United States)

    2001-01-01

    This prostate cancer construct was grown during NASA-sponsored bioreactor studies on Earth. Cells are attached to a biodegradable plastic lattice that gives them a head start in growth. Prostate tumor cells are to be grown in a NASA-sponsored Bioreactor experiment aboard the STS-107 Research-1 mission in 2002. Dr. Leland Chung of the University of Virginia is the principal investigator. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Credit: NASA and the University of Virginia.

  12. Methane production in simulated hybrid bioreactor landfill.

    Science.gov (United States)

    Xu, Qiyong; Jin, Xiao; Ma, Zeyu; Tao, Huchun; Ko, Jae Hac

    2014-09-01

    The aim of this work was to study a hybrid bioreactor landfill technology for landfill methane production from municipal solid waste. Two laboratory-scale columns were operated for about ten months to simulate an anaerobic and a hybrid landfill bioreactor, respectively. Leachate was recirculated into each column but aeration was conducted in the hybrid bioreactor during the first stage. Results showed that leachate pH in the anaerobic bioreactor maintained below 6.5, while in the hybrid bioreactor quickly increased from 5.6 to 7.0 due to the aeration. The temporary aeration resulted in lowering COD and BOD5 in the leachate. The volume of methane collected from the hybrid bioreactor was 400 times greater than that of the anaerobic bioreactor. Also, the methane production rate of the hybrid bioreactor was improved within a short period of time. After about 10 months' operation, the total methane production in the hybrid bioreactor was 212 L (16 L/kgwaste).

  13. Optimizing of Culture Conditionin Horizontal Rotating Bioreactor

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1 IntroductionBioreactor is the most important equipment in tissue engineering. It can mimic the micro-environment of cell growth in vitro. At present, horizontal rotating bioreactor is the most advanced equipment for cell culture in the world. 2 Rotating bioreactors2.1 Working principleThere are two kinds of horizontal rotating bioreactor: HARV(high aspect ratio vessel) and RCCS (rotary cell culture system). It is drived by step motor with horizontal rotation, the culture medium and cell is filled between ...

  14. Review of nonconventional bioreactor technology

    Energy Technology Data Exchange (ETDEWEB)

    Turick, C.E.; Mcllwain, M.E.

    1993-09-01

    Biotechnology will significantly affect many industrial sectors in the future. Industrial sectors that will be affected include pharmaceutical, chemical, fuel, agricultural, and environmental remediation. Future research is needed to improve bioprocessing efficiency and cost-effectiveness in order to compete with traditional technologies. This report describes recent advances in bioprocess technologies and bioreactor designs and relates them to problems encountered in many industrial bioprocessing operations. The primary focus is directed towards increasing gas and vapor transfer for enhanced bioprocess kinetics as well as unproved by-product separation and removal. The advantages and disadvantages of various conceptual designs such as hollow-fiber, gas-phase, hyperbaric/hypobaric, and electrochemical bioreactors are also discussed. Specific applications that are intended for improved bioprocesses include coal desulfurization, coal liquefaction, soil bioremediation, biomass conversion to marketable chemicals, biomining, and biohydrometallurgy as well as bioprocessing of gases and vapors.

  15. Monolithic Continuous-Flow Bioreactors

    Science.gov (United States)

    Stephanopoulos, Gregory; Kornfield, Julia A.; Voecks, Gerald A.

    1993-01-01

    Monolithic ceramic matrices containing many small flow passages useful as continuous-flow bioreactors. Ceramic matrix containing passages made by extruding and firing suitable ceramic. Pores in matrix provide attachment medium for film of cells and allow free movement of solution. Material one not toxic to micro-organisms grown in reactor. In reactor, liquid nutrients flow over, and liquid reaction products flow from, cell culture immobilized in one set of channels while oxygen flows to, and gaseous reaction products flow from, culture in adjacent set of passages. Cells live on inner surfaces containing flowing nutrient and in pores of walls of passages. Ready access to nutrients and oxygen in channels. They generate continuous high yield characteristic of immobilized cells, without large expenditure of energy otherwise incurred if necessary to pump nutrient solution through dense biomass as in bioreactors of other types.

  16. Denitrification using immersed membrane bioreactors

    OpenAIRE

    McAdam, Ewan J.

    2008-01-01

    Nitrate is practically ubiquitous in waters abstracted for municipal potable water production in Europe due to decades of intensive agricultural practice. Ion exchange is principally selected to target abstracted waters with elevated nitrate concentrations. However, the cost associated with disposal of the waste stream has re-ignited interest in destructive rather concentrative technologies. This thesis explores the potential of membrane bioreactor (MBR) technology for the remo...

  17. Measures to influence nitric oxide formation and alkali release in coal dust combustion under pressure; Massnahmen zur Beeinflussung der Stickoxidbildung und Alkalienfreisetzung bei der Kohlenstaubdruckverbrennung

    Energy Technology Data Exchange (ETDEWEB)

    Thielen, W.; Niepel, H. [Steinmueller (L.u.C.) GmbH, Gummersbach (Germany)

    1999-09-01

    Messrs. Steinmueller are making the following contributions to the Dorsten experimental plant: Development of pressure burner and combustion chamber, fuel supply and flue gas analysis, especially the development of a high-temperature flue gas tapping unit at the end of the hot reaction zone. Burner development should always aim at complete converstion of the fuel and minimal pollutant emissions, as well as stable combustion over a wide range of operating conditons and maximum reliability in case of disturbances. Tools for development and experiment analysis are flow measurements in isothermal models, numerical flow and radiation excchange calculation programs, and reference data from the hot operation under pressure of the small-scale Dorsten pilot plant. The contribution presents the results of the burner experiments with a view to nitric oxide and alkali emissions; finally, the effects of different influencing parameters on combustion control and on the still unresolved fields of investigation are indicated. [Deutsch] Die Druckkohlenstaubfeuerung erschliesst fuer den Brennstoff Kohle durch Nutzung des Gas- und Dampfturbinenprozesses Kraftwerkswirkungsgrade im Bereich von 50 % und mehr. Dabei soll das unter Druck verbrannte Rauchgas nach Abscheidung aller schaedlichen Bestandteile, insbesondere der Asche, die in diesem Temperaturbereich durchweg schmelzfluessig vorliegt, direkt auf die Gasturbine geleitet werden. Mit Foerderung des Bundes (seinerzeit BMFT) wurde unter Beteiligung der GHS Essen, mehrerer Industriepartner und Energieversorger am Zechenstandort Dorsten eine Kleinpilotanlage mit einer thermischen Leistung von ca 1 MW errichtet und seither betrieben. Der Forschungsschwerpunkt der L. und C. Steinmueller GmbH richtete sich darin auf die Thematik Kohleumwandlung. Die Aktivitaeten umfssten die Bereiche Druckbrenner- und Brennkammerentwicklung, die Brennstoffversorgung und die Rauchgasanalytik, hier insbesondere die Entwicklung einer Hochtemperatur

  18. Bioreactors for Plant Embryogenesis and Beyond.

    Science.gov (United States)

    Fei, Liwen; Weathers, Pamela

    2016-01-01

    A variety of different bioreactors have been developed for use in initiating and cultivating somatic embryos. The various designs for embryogenesis and culture are critically evaluated here. Bioreactor optimization and operation methods are also described along with recommendations for use based on desired outcome.

  19. BIOREACTOR DESIGN - OUTER LOOP LANDFILL, LOUISVILLE, KY

    Science.gov (United States)

    Bioreactor field demonstration projects are underway at the Outer Loop Landfill in Louisville, KY, USA. The research effort is a cooperative research effort between US EPA and Waste Management Inc. Two primary kinds of municipal waste bioreactors are under study at this site. ...

  20. Use of dexpanthenol and aloe vera to influence the irradiation response of the oral mucous membrane (mouse); Beeinflussung der Strahlenreaktion der Mundschleimhaut (Maus) durch Dexpanthenol {+-} Aloe vera

    Energy Technology Data Exchange (ETDEWEB)

    Schlichting, S. [Klinik und Poliklinik fuer Strahlentherapie und Radioonkologie, Dresden Univ. (Germany); Spekl, K.; Doerr, W. [Klinik und Poliklinik fuer Strahlentherapie und Radioonkologie, Dresden Univ. (Germany)]|[Experimentelles Zentrum, Medizinische Fakultaet Carl Gustav Carus, Dresden Univ. (Germany)

    2004-07-01

    In summarising the outcome of the present study it can be said spraying the agent on the oral mucous membrane once a day had an effect on the incidence of mucous membrane ulceration in the case of both placebo and dexpanthenol treatment. However, there was no significant difference between placebo and dexpanthenol treatment, the only finding being a slight prolongation of latency time through aloe vera. These experimental findings give good reason to critically reconsider the clinical use of dexpanthenol as a supportive treatment for the prevention of radiogenic mucositis enoralis following irradiation of tumours in the head and neck region. However thorough oral lavage is an effective means of moderating the irradiation response of the oral mucous membrane. [German] Zusammenfassend ist festzustellen, dass in den vorliegenden Versuchen mit einmal taeglichem Aufspruehen des Praeparates auf die Mundschleimhaut sowohl die Placebo - wie auch die Dexpanthenol-Behandlung die Inzidenz von Schleimhautulzerationen modifiziert hat; zwischen Placebo- und Dexpanthenol-Behandlung ergab sich jedoch kein signifikanter Unterschied. Lediglich eine geringe Verlaengerung der Latenzzeit durch Aloe vera war zu beobachten. Auf der Basis dieser experimentellen Ergebnisse muss der klinische Einsatz von Dexpanthenol im Rahmen der Supportivtherapie zur Prophylaxe der radiogenen Mucositis enoralis bei der Bestrahlung von Kopf-Hals-Tumoren kritisch ueberdacht werden. Regelmaessige, intensive Mundspuelungen sind jedoch ein probates Mittel zur Verminderung der Strahlenreaktion der Mundschleimhaut. (orig.)

  1. Tissue grown in space in NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    For 5 days on the STS-70 mission, a bioreactor cultivated human colon cancer cells, such as the culture section shown here, which grew to 30 times the volume of control specimens grown on Earth. This significant result was reproduced on STS-85 which grew mature structures that more closely match what are found in tumors in humans. The two white circles within the tumor are part of a plastic lattice that helped the cells associate. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  2. Des guides et des cartes

    OpenAIRE

    Mathieu, Patricia; Maryvonne LE BERRE; Jean-Marc ROCHE

    1987-01-01

    Consultés pour leurs références régionales ou locales, les guides touristiques donnent aussi une vision globale de la France qui est rarement perçue par l'utilisateur. Différents types de représentations cartographiques ont été choisis pour montrer, à partir d'informations simples, découpage en «régions» touristiques, étoilement des sites et des espaces touristiques, cette image de la France.

  3. Des guides et des cartes

    Directory of Open Access Journals (Sweden)

    Patricia MATHIEU

    1987-12-01

    Full Text Available Consultés pour leurs références régionales ou locales, les guides touristiques donnent aussi une vision globale de la France qui est rarement perçue par l'utilisateur. Différents types de représentations cartographiques ont été choisis pour montrer, à partir d'informations simples, découpage en «régions» touristiques, étoilement des sites et des espaces touristiques, cette image de la France.

  4. Tubular membrane bioreactors for biotechnological processes.

    Science.gov (United States)

    Wolff, Christoph; Beutel, Sascha; Scheper, Thomas

    2013-02-01

    This article is an overview of bioreactors using tubular membranes such as hollow fibers or ceramic capillaries for cultivation processes. This diverse group of bioreactor is described here in regard to the membrane materials used, operational modes, and configurations. The typical advantages of this kind of system such as environments with low shear stress together with high cell densities and also disadvantages like poor oxygen supply are summed up. As the usage of tubular membrane bioreactors is not restricted to a certain organism, a brief overview of various applications covering nearly all types of cells from prokaryotic to eukaryotic cells is also given here. PMID:23224587

  5. Spatial Experiment Technologies Suitable for Unreturnable Bioreactor

    Science.gov (United States)

    Zhang, Tao; Zheng, Weibo; Tong, Guanghui

    2016-07-01

    The system composition and main function of the bioreactor piggybacked on TZ cargo transport spacecraft are introduced briefly in the paper.The spatial experiment technologies which are suitable for unreturnable bioreactor are described in detail,including multi-channel liquid transportion and management,multi-type animal cells circuit testing,dynamic targets microscopic observation in situ etc..The feasibility and effectiveness of these technologies which will be used in space experiment in bioreactor are verified in tests and experiments on the ground.

  6. Development of Fundamental Technologies for Micro Bioreactors

    Science.gov (United States)

    Sato, Kiichi; Kitamori, Takehiko

    This chapter reviews the development of fundamental technologies required for microchip-based bioreactors utilizing living mammalian cells and pressure driven flow. The most important factor in the bioreactor is the cell culture. For proper cell culturing, continuous medium supply from a microfluidic channel and appropriate modification of the channel surface to accommodate cell attachment is required. Moreover, the medium flow rate should be chosen carefully, because shear stress affects cell activity. The techniques presented here could be applied to the development of micro bioreactors such as microlivers, pigment production by plant cells, and artificial insemination.

  7. An innovative membrane bioreactor for methane biohydroxylation.

    Science.gov (United States)

    Pen, N; Soussan, L; Belleville, M-P; Sanchez, J; Charmette, C; Paolucci-Jeanjean, D

    2014-12-01

    In this study, a membrane bioreactor (MBR) was developed for efficient, safe microbial methane hydroxylation with Methylosinus trichosporium OB3b. This innovative MBR, which couples a bioreactor with two gas/liquid macroporous membrane contactors supplying the two gaseous substrates (methane and oxygen) was operated in fed-batch mode. The feasibility and the reproducibility of this new biohydroxylation process were first demonstrated. The mass transfer within this MBR was twice that observed in a batch reactor in similar conditions. The productivity reached with this MBR was 75±25mgmethanol(gdrycell)(-1)h(-1). Compared to the literature, this value is 35times higher than that obtained with the only other fed-batch membrane bioreactor reported, which was run with dense membranes, and is comparable to those obtained with bioreactors fed by bubble-spargers. However, in the latter case, an explosive gas mixture can be formed, a problem that is avoided with the MBR.

  8. In vivo bioreactors for mandibular reconstruction.

    Science.gov (United States)

    Tatara, A M; Wong, M E; Mikos, A G

    2014-12-01

    Large mandibular defects are difficult to reconstruct with good functional and aesthetic outcomes because of the complex geometry of craniofacial bone. While the current gold standard is free tissue flap transfer, this treatment is limited in fidelity by the shape of the harvested tissue and can result in significant donor site morbidity. To address these problems, in vivo bioreactors have been explored as an approach to generate autologous prefabricated tissue flaps. These bioreactors are implanted in an ectopic site in the body, where ossified tissue grows into the bioreactor in predefined geometries and local vessels are recruited to vascularize the developing construct. The prefabricated flap can then be harvested with vessels and transferred to a mandibular defect for optimal reconstruction. The objective of this review article is to introduce the concept of the in vivo bioreactor, describe important preclinical models in the field, summarize the human cases that have been reported through this strategy, and offer future directions for this exciting approach.

  9. Energy efficiency in membrane bioreactors.

    Science.gov (United States)

    Barillon, B; Martin Ruel, S; Langlais, C; Lazarova, V

    2013-01-01

    Energy consumption remains the key factor for the optimisation of the performance of membrane bioreactors (MBRs). This paper presents the results of the detailed energy audits of six full-scale MBRs operated by Suez Environnement in France, Spain and the USA based on on-site energy measurement and analysis of plant operation parameters and treatment performance. Specific energy consumption is compared for two different MBR configurations (flat sheet and hollow fibre membranes) and for plants with different design, loads and operation parameters. The aim of this project was to understand how the energy is consumed in MBR facilities and under which operating conditions, in order to finally provide guidelines and recommended practices for optimisation of MBR operation and design to reduce energy consumption and environmental impacts.

  10. Thin film bioreactors in space

    Science.gov (United States)

    Hughes-Fulford, M.; Scheld, H. W.

    1989-01-01

    Studies from the Skylab, SL-3 and D-1 missions have demonstrated that biological organisms grown in microgravity have changes in basic cellular functions such as DNA, mRNA and protein synthesis, cytoskeleton synthesis, glucose utilization, and cellular differentiation. Since microgravity could affect prokaryotic and eukaryotic cells at a subcellular and molecular level, space offers an opportunity to learn more about basic biological systems with one inmportant variable removed. The thin film bioreactor will facilitate the handling of fluids in microgravity, under constant temperature and will allow multiple samples of cells to be grown with variable conditions. Studies on cell cultures grown in microgravity would make it possible to identify and quantify changes in basic biological function in microgravity which are needed to develop new applications of orbital research and future biotechnology.

  11. NASA Bioreactors Advance Disease Treatments

    Science.gov (United States)

    2009-01-01

    The International Space Station (ISS) is falling. This is no threat to the astronauts onboard, however, because falling is part of the ISS staying in orbit. The absence of gravity beyond the Earth s atmosphere is actually an illusion; at the ISS s orbital altitude of approximately 250 miles above the surface, the planet s gravitational pull is only 12-percent weaker than on the ground. Gravity is constantly pulling the ISS back to Earth, but the space station is also constantly traveling at nearly 18,000 miles per hour. This means that, even though the ISS is falling toward Earth, it is moving sideways fast enough to continually miss impacting the planet. The balance between the force of gravity and the ISS s motion creates a stable orbit, and the fact that the ISS and everything in it including the astronauts are falling at an equal rate creates the condition of weightlessness called microgravity. The constant falling of objects in orbit is not only an important principle in space, but it is also a key element of a revolutionary NASA technology here on Earth that may soon help cure medical ailments from heart disease to diabetes. In the mid-1980s, NASA researchers at Johnson Space Center were investigating the effects of long-term microgravity on human tissues. At the time, the Agency s shuttle fleet was grounded following the 1986 Space Shuttle Challenger disaster, and researchers had no access to the microgravity conditions of space. To provide a method for recreating such conditions on Earth, Johnson s David Wolf, Tinh Trinh, and Ray Schwarz developed that same year a horizontal, rotating device called a rotating wall bioreactor that allowed the growth of human cells in simulated weightlessness. Previously, cell cultures on Earth could only be grown two-dimensionally in Petri dishes, because gravity would cause the multiplying cells to sink within their growth medium. These cells do not look or function like real human cells, which grow three-dimensionally in

  12. Colon tumor cells grown in NASA Bioreactor

    Science.gov (United States)

    2001-01-01

    These photos compare the results of colon carcinoma cells grown in a NASA Bioreactor flown on the STS-70 Space Shuttle in 1995 flight and ground control experiments. The cells grown in microgravity (left) have aggregated to form masses that are larger and more similar to tissue found in the body than the cells cultured on the ground (right). The principal investigator is Milburn Jessup of the University of Texas M. D. Anderson Cancer Center. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Cell constructs grown in a rotating bioreactor on Earth (left) eventually become too large to stay suspended in the nutrient media. In the microgravity of orbit, the cells stay suspended. Rotation then is needed for gentle stirring to replenish the media around the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). Credit: NASA and University of Texas M. D. Anderson Cancer Center.

  13. New bioreactors systems for pharmacological screening

    OpenAIRE

    Vozzi, Federico

    2007-01-01

    Bioreactors, biotechnological devices for in vitro cell cultures with dynamic conditions, have the potential to provide information on local cell behavior and function. The development of bioreactors could lead to a multitude of applications from drug testing and development, tissue engineering and basic research to the identification of new and alternative therapies for many disorders. High quality, reliable, in vitro data also provide a shift in focus from large scale animal testing to the ...

  14. Advanced microscale bioreactor system: a representative scale-down model for bench-top bioreactors.

    Science.gov (United States)

    Hsu, Wei-Ting; Aulakh, Rigzen P S; Traul, Donald L; Yuk, Inn H

    2012-12-01

    In recent years, several automated scale-down bioreactor systems have been developed to increase efficiency in cell culture process development. ambr™ is an automated workstation that provides individual monitoring and control of culture dissolved oxygen and pH in single-use, stirred-tank bioreactors at a working volume of 10-15 mL. To evaluate the ambr™ system, we compared the performance of four recombinant Chinese hamster ovary cell lines in a fed-batch process in parallel ambr™, 2-L bench-top bioreactors, and shake flasks. Cultures in ambr™ matched 2-L bioreactors in controlling the environment (temperature, dissolved oxygen, and pH) and in culture performance (growth, viability, glucose, lactate, Na(+), osmolality, titer, and product quality). However, cultures in shake flasks did not show comparable performance to the ambr™ and 2-L bioreactors.

  15. Tubular bioreactor and its application; Tubular bioreactor to sono tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Endo, I.; Nagamune, T. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering; Yuki, K. [Nikka Whisky Distilling Co. Ltd. Tokyo (Japan); Inaba, H. [Sumitomo Heavy Industries, Ltd., Tokyo (Japan)

    1994-09-05

    The loop type tubular bioreactor (TBR) was developed where biocatalysts are trapped in the reactor by membrane module. A UF membrane or MF membrane and crossflow filtration were adopted for the membrane module, and the reactor loop was composed of four membrane modules. The reactor was operated at 2-4 m/s in membrane surface velocity and 300-400 kPa in filtration pressure. As the result of the high-density culture of lactic acid bacteria and yeast, a biomass concentration was more than 10 times that in batch culture, suggesting the remarkable enhancement of a production efficiency. As the result of the continuous fermentation of cider, the fast fermentation more than 60 times that in conventional ones was obtained together with the same quality as conventional ones. Such a fast fermentation was probably achieved by yeast suspended in the fermenter of TBR, by yeast hardly affected physico-chemically as compared with immobilized reactors, and by small effect of mass transfer on reaction systems. 4 refs., 6 figs.

  16. Optimizing of Culture Condition in Horizontal Rotating Bioreactor

    Institute of Scientific and Technical Information of China (English)

    Yan-Fang ZHANG; Huai-Qing CHEN; Hua HUANG

    2005-01-01

    @@ 1 Introduction Bioreactor is the most important equipment in tissue engineering. It can mimic the micro-environment of cell growth in vitro. At present, horizontal rotating bioreactor is the most advanced equipment for cell culture in the world.

  17. Open source software to control Bioflo bioreactors.

    Directory of Open Access Journals (Sweden)

    David A Burdge

    Full Text Available Bioreactors are designed to support highly controlled environments for growth of tissues, cell cultures or microbial cultures. A variety of bioreactors are commercially available, often including sophisticated software to enhance the functionality of the bioreactor. However, experiments that the bioreactor hardware can support, but that were not envisioned during the software design cannot be performed without developing custom software. In addition, support for third party or custom designed auxiliary hardware is often sparse or absent. This work presents flexible open source freeware for the control of bioreactors of the Bioflo product family. The functionality of the software includes setpoint control, data logging, and protocol execution. Auxiliary hardware can be easily integrated and controlled through an integrated plugin interface without altering existing software. Simple experimental protocols can be entered as a CSV scripting file, and a Python-based protocol execution model is included for more demanding conditional experimental control. The software was designed to be a more flexible and free open source alternative to the commercially available solution. The source code and various auxiliary hardware plugins are publicly available for download from https://github.com/LibourelLab/BiofloSoftware. In addition to the source code, the software was compiled and packaged as a self-installing file for 32 and 64 bit windows operating systems. The compiled software will be able to control a Bioflo system, and will not require the installation of LabVIEW.

  18. Hydrodynamics research of wastewater treatment bioreactors

    Institute of Scientific and Technical Information of China (English)

    REN Nan-qi; ZHANG Bing; ZHOU Xue-fei

    2009-01-01

    To optimize the design and improve the performance of wastewater treatment bioreactors, the review concerning the hydrodynamics explored by theoretical equations, process experiments, modeling of the hydrody-namics and flow field measurement is presented. Results of different kinds of experiments show that the hydro-dynamic characteristics can affect sludge characteristics, mass transfer and reactor performance significantly. A-long with the development of theoretical equations, turbulence models including large eddy simulation models and Reynolds-averaged Navier-Stokes (RANS) models are widely used at present. Standard and modified k-ε models are the most widely used eddy viscosity turbulence models for simulating flows in bioreactors. Numericalsimulation of hydrodynamics is proved to be efficient for optimizing design and operation. The development of measurement techniques with high accuracy and low intrusion enables the flow filed in the bioreactors to be transparent. Integration of both numerical simulation and experimental measurement can describe the hydrody-namics very well.

  19. Evolution of Bioreactors for Extracorporeal Liver Support

    Directory of Open Access Journals (Sweden)

    Vilkova Е.V.

    2014-03-01

    Full Text Available The development of effective extracorporeal liver support systems in acute and chronic hepatic failure for transplantology purposes and in toxic injuries is a promising direction in modern biomedical studies. Widely used techniques are based on physicochemical interactions of biological molecules, and able to perform a detoxification function only (hemodialysis, hemofiltration, hemodiafiltration, sorption, albumin dialysis, plasmapheresis. However, support systems combining both blood/plasma perfusion and cellular technologies to maintain metabolic, synthetic and regulatory hepatic functions — “artificial liver” systems — are being extensively developed in recent decades. The review describes the main types of cell lines cultured to occupy bioreactors, various technological concepts for bioreactor design (dynamic, static, scaffold-carriers as part of bioreactors (structure, biochemical composition. The study gives metabolic characteristics of a cellular component of “bioartificial liver”: nourishment, oxygen saturation. Various types of existing extracorporeal support systems, their evolution, and preclinical and clinical test results are presented.

  20. Model studies and numerical simulations on nitrate reduction in a bioreactor; Modellbetrachtung und numerische Simulationen zur Nitrat-Reduktion in einem Bioreaktor

    Energy Technology Data Exchange (ETDEWEB)

    Ghergut, I. [Inst. fuer angew. Math., Rumaenische Akad. d. Wiss. (Romania); Maloszewski, P.; Seiler, K.P. [GSF - Forschungszentrum fuer Umwelt und Gesundheit GmbH, Neuherberg (Germany). Inst. fuer Hydrologie; Naumann, U.

    2001-11-01

    Naumann carried out denitrification studies on bacteria in a bioreactor providing a groundwater-like, anoxic environment which was so adjusted as to sustain a stable, denitrifying biocoenosis. This bioreactor consists of a column containing water from a karst spring and drill core material from the mass lime of the Franconian Jurassic. There is a flow of spring water through the bioreactor. This paper is an endeavour to formulate classical models on nutrient consumption and population dynamics in this bioreactor. The processes in the bioreactor are determined quantitatively by means of simple partial differential equations. This leads to a calibrated mathematical model which serves as a basis for discussing and specifying unresolved questions. [German] Naumann fuehrte Denitrifikationsuntersuchungen von Bakterien in einem unter grundwasseraehnlichen, sauerstoffreien Bedingungen funktionierenden Bioreaktor durch, in dem Voraussetzungen einer stabilen denitrifizierenden Organismengemeinschaft geschaffen wurden. Dieser Bioreaktor besteht aus einer Saeule mit Wasser aus einer Karstquelle und Bohrkernmaterial aus dem Massenkalk des fraenkischen Juras und wird vom Quellwasser durchstroemt. Im Folgenden wird versucht, klassische Modellansaetze zum Naehrstoffverbrauch und zur Populationsdynamik fuer das Geschehen in diesem Bioreaktor zu artikulieren; das Bioreaktorgeschehen wird durch einfache partielle Differential-Gleichungen (PDG) quantitativ erfasst. Das so kalibrierte mathematische Modell wird schliesslich dazu benutzt noch offene Fragen anzudiskutieren bzw. einzuengen. (orig.)

  1. Bioreactor and methods for producing synchronous cells

    Science.gov (United States)

    Helmstetter, Charles E. (Inventor); Thornton, Maureen (Inventor); Gonda, Steve (Inventor)

    2005-01-01

    Apparatus and methods are directed to a perfusion culture system in which a rotating bioreactor is used to grow cells in a liquid culture medium, while these cells are attached to an adhesive-treated porous surface. As a result of this arrangement and its rotation, the attached cells divide, with one cell remaining attached to the substrate, while the other cell, a newborn cell is released. These newborn cells are of approximately the same age, that are collected upon leaving the bioreactor. The populations of newborn cells collected are of synchronous and are minimally, if at all, disturbed metabolically.

  2. Sulfate-reducing bacteria in anaerobic bioreactors.

    NARCIS (Netherlands)

    Oude Elferink, S.J.W.H.

    1998-01-01

    The treatment of industrial wastewaters containing high amounts of easily degradable organic compounds in anaerobic bioreactors is a well-established process. Similarly, wastewaters which in addition to organic compounds also contain sulfate can be treated in this way. For a long time, the occurrenc

  3. Computational fluid dynamics simulation of bioreactors

    Directory of Open Access Journals (Sweden)

    Bjørn H. Hjertager

    1995-10-01

    Full Text Available Multi-dimensional models of flow processes in bioreactors are presented. Particular emphasis is given to models that use the two-fluid technique. The models use a two-equation turbuluence model and a Monod type kinetic reaction model. Predictions are given for both bubble column and mechanically stirred reactors.

  4. Vortex breakdown in a truncated conical bioreactor

    DEFF Research Database (Denmark)

    Balci, Adnan; Brøns, Morten; Herrada, Miguel A.;

    2015-01-01

    This numerical study explains the eddy formation and disappearance in a slow steady axisymmetric air–water flow in a vertical truncated conical container, driven by the rotating top disk. Numerous topological metamorphoses occur as the water height, Hw, and the bottom-sidewall angle, α, vary. It ...... are of fundamental interest and can be relevant for aerial bioreactors....

  5. Denitrifying bioreactor clogging potential during wastewater treatment

    Science.gov (United States)

    Chemoheterotrophic denitrification technologies using woodchips as a solid carbon source (i.e., woodchip bioreactors) have been widely trialed for treatment of diffuse-source agricultural nitrogen pollution. There is growing interest in the use of this simple, relatively low-cost biological wastewat...

  6. LANDFILL BIOREACTOR PERFORMANCE, SECOND INTERIM REPORT

    Science.gov (United States)

    A bioreactor landfill is a landfill that is operated in a manner that is expected to increase the rate and extent of waste decomposition, gas generation, and settlement compared to a traditional landfill. This Second Interim Report was prepared to provide an interpretation of fie...

  7. Critical Review of Membrane Bioreactor Models

    DEFF Research Database (Denmark)

    Naessens, W.; Maere, T.; Ratkovich, Nicolas Rios;

    2012-01-01

    Membrane bioreactor technology exists for a couple of decades, but has not yet overwhelmed the market due to some serious drawbacks of which operational cost due to fouling is the major contributor. Knowledge buildup and optimisation for such complex systems can heavily benefit from mathematical...

  8. MONITORING APPROACHES FOR BIOREACTOR LANDFILLS - Report

    Science.gov (United States)

    Experimental bioreactor landfill operations at operating Municipal Solid Waste (MSW) landfills can be approved under the research development and demonstration (RD&D) provisions of 30CFR 258.4. To provide a basis for consistent data collection for future decision-making in suppor...

  9. Engineering skeletal muscle tissue in bioreactor systems

    Institute of Scientific and Technical Information of China (English)

    An Yang; Li Dong

    2014-01-01

    Objective To give a concise review of the current state of the art in tissue engineering (TE) related to skeletal muscle and kinds of bioreactor environment.Data sources The review was based on data obtained from the published articles and guidelines.Study selection A total of 106 articles were selected from several hundred original articles or reviews.The content of selected articles is in accordance with our purpose and the authors are authorized scientists in the study of engineered muscle tissue in bioreactor.Results Skeletal muscle TE is a promising interdisciplinary field which aims at the reconstruction of skeletal muscle loss.Although numerous studies have indicated that engineering skeletal muscle tissue may be of great importance in medicine in the near future,this technique still represents a limited degree of success.Since tissue-engineered muscle constructs require an adequate connection to the vascular system for efficient transport of oxygen,carbon dioxide,nutrients and waste products.Moreover,functional and clinically applicable muscle constructs depend on adequate neuromuscular junctions with neural calls.Third,in order to engineer muscle tissue successfully,it may be beneficial to mimic the in vivo environment of muscle through association with adequate stimuli from bioreactors.Conclusion Vascular system and bioreactors are necessary for development and maintenance of engineered muscle in order to provide circulation within the construct.

  10. Establishing Liver Bioreactors for In Vitro Research.

    Science.gov (United States)

    Rebelo, Sofia P; Costa, Rita; Sousa, Marcos F Q; Brito, Catarina; Alves, Paula M

    2015-01-01

    In vitro systems that can effectively model liver function for long periods of time are fundamental tools for preclinical research. Nevertheless, the adoption of in vitro research tools at the earliest stages of drug development has been hampered by the lack of culture systems that offer the robustness, scalability, and flexibility necessary to meet industry's demands. Bioreactor-based technologies, such as stirred tank bioreactors, constitute a feasible approach to aggregate hepatic cells and maintain long-term three-dimensional cultures. These three-dimensional cultures sustain the polarity, differentiated phenotype, and metabolic performance of human hepatocytes. Culture in computer-controlled stirred tank bioreactors allows the maintenance of physiological conditions, such as pH, dissolved oxygen, and temperature, with minimal fluctuations. Moreover, by operating in perfusion mode, gradients of soluble factors and metabolic by-products can be established, aiming at resembling the in vivo microenvironment. This chapter provides a protocol for the aggregation and culture of hepatocyte spheroids in stirred tank bioreactors by applying perfusion mode for the long-term culture of human hepatocytes. This in vitro culture system is compatible with feeding high-throughput screening platforms for the assessment of drug elimination pathways, being a useful tool for toxicology research and drug development in the preclinical phase. PMID:26272143

  11. Anaerobic membrane bioreactors: Are membranes really necessary?

    NARCIS (Netherlands)

    Davila, M.; Kassab, G.; Klapwijk, A.; Lier, van J.B.

    2008-01-01

    Membranes themselves represent a significant cost for the full scale application of anaerobic membrane bioreactors (AnMBR). The possibility of operating an AnMBR with a self-forming dynamic membrane generated by the substances present in the reactor liquor would translate into an important saving. A

  12. Establishing Liver Bioreactors for In Vitro Research.

    Science.gov (United States)

    Rebelo, Sofia P; Costa, Rita; Sousa, Marcos F Q; Brito, Catarina; Alves, Paula M

    2015-01-01

    In vitro systems that can effectively model liver function for long periods of time are fundamental tools for preclinical research. Nevertheless, the adoption of in vitro research tools at the earliest stages of drug development has been hampered by the lack of culture systems that offer the robustness, scalability, and flexibility necessary to meet industry's demands. Bioreactor-based technologies, such as stirred tank bioreactors, constitute a feasible approach to aggregate hepatic cells and maintain long-term three-dimensional cultures. These three-dimensional cultures sustain the polarity, differentiated phenotype, and metabolic performance of human hepatocytes. Culture in computer-controlled stirred tank bioreactors allows the maintenance of physiological conditions, such as pH, dissolved oxygen, and temperature, with minimal fluctuations. Moreover, by operating in perfusion mode, gradients of soluble factors and metabolic by-products can be established, aiming at resembling the in vivo microenvironment. This chapter provides a protocol for the aggregation and culture of hepatocyte spheroids in stirred tank bioreactors by applying perfusion mode for the long-term culture of human hepatocytes. This in vitro culture system is compatible with feeding high-throughput screening platforms for the assessment of drug elimination pathways, being a useful tool for toxicology research and drug development in the preclinical phase.

  13. Continuous-Flow Gas-Phase Bioreactors

    Science.gov (United States)

    Wise, Donald L.; Trantolo, Debra J.

    1994-01-01

    Continuous-flow gas-phase bioreactors proposed for biochemical, food-processing, and related industries. Reactor contains one or more selected enzymes dehydrated or otherwise immobilized on solid carrier. Selected reactant gases fed into reactor, wherein chemical reactions catalyzed by enzyme(s) yield product biochemicals. Concept based on discovery that enzymes not necessarily placed in traditional aqueous environments to function as biocatalysts.

  14. Bioreactors in tissue engineering - principles, applications and commercial constraints.

    Science.gov (United States)

    Hansmann, Jan; Groeber, Florian; Kahlig, Alexander; Kleinhans, Claudia; Walles, Heike

    2013-03-01

    Bioreactor technology is vital for tissue engineering. Usually, bioreactors are used to provide a tissue-specific physiological in vitro environment during tissue maturation. In addition to this most obvious application, bioreactors have the potential to improve the efficiency of the overall tissue-engineering concept. To date, a variety of bioreactor systems for tissue-specific applications have been developed. Of these, some systems are already commercially available. With bioreactor technology, various functional tissues of different types were generated and cultured in vitro. Nevertheless, these efforts and achievements alone have not yet led to many clinically successful tissue-engineered implants. We review possible applications for bioreactor systems within a tissue-engineering process and present basic principles and requirements for bioreactor development. Moreover, the use of bioreactor systems for the expansion of clinically relevant cell types is addressed. In contrast to cell expansion, for the generation of functional three-dimensional tissue equivalents, additional physical cues must be provided. Therefore, bioreactors for musculoskeletal tissue engineering are discussed. Finally, bioreactor technology is reviewed in the context of commercial constraints.

  15. Strukturmerkmale des chinesischen Kapitalismus

    OpenAIRE

    Brink, Tobias ten

    2010-01-01

    Für ein Verständnis der chinesischen Wirtschaft ist es hilfreich, das theoretische Instrumentarium der Kapitalismusforschung nutzbar zu machen. Es ermöglicht eine fundierte Charakterisierung des chinesischen Systems als einer eigentümlichen Spielart des Kapitalismus – eines marktliberalen, wettbewerbsgetriebenen Staatskapitalismus. Zu den Eigentümlichkeiten des chinesischen Kapitalismus gehören ein dynamischer Staatsdirigismus, eine besondere Form des Wettbewerbs und der privat-öffentlichen U...

  16. Remittances | Transferts des migrants

    OpenAIRE

    2012-01-01

    Major Recipients of Remittances (in Million USD, 2008) Principaux pays bénéficiaires des transferts des migrants (en millions USD, 2008) ­ Migrants’ Remittances per Capita (in USD, 2008) Transferts des migrants par habitant (en USD, 2008) Source: World Bank, migration and remittances data.

  17. Die Thrombolysetherapie des ST-Streckenhebungsinfarktes 2002

    Directory of Open Access Journals (Sweden)

    Huber K

    2002-01-01

    der GUSTO-3-Studie (t-PA vs. r-PA und in der ASSENT-2-Studie (t-PA VS. TNK-tPA konnte eine gleich gute Effektivität von t-PA und seinen Mutanten nachgewiesen werden. Der Vorteil von r-PA und TNK-tPA lag in erster Linie in der einfacheren Applikationsweise. TNK-tPA wird körpergewichtsadaptiert verabreicht und weist bei Hochrisikopatienten (unter 75jährige, unter 67 kg schwere Frauen die verhältnismäßig geringste intrazerebrale Blutungsrate auf. In Pilotstudien konnte gezeigt werden, daß die Kombination einer halben Dosis eines Fibrinolytikums mit einer Volldosis eines GP IIb/IIIa-Blockers zu einer deutlich höheren TIMI-Grad 3-Flußrate (65 bis 78 % führt (TIMI-14-Studie: t-PA oder r-PA + Abciximab, SPEED-Studie: r-PA + Abciximab; INTRO-AMI-Studie: t-PA + Eptifibatid; INTEGRITI-Studie: TNK-tPA + Eptifibatid. Die beiden bisher durchgeführten prospektiven klinischen Vergleichsstudien haben diese Hoffnungen aber nicht erfüllt und zu keiner Verbesserung der harten klinischen Endpunkte geführt (GUSTO V-, ASSENT-3-Studie. Erfolge konnten aber für die Kombination Fibrinolyse + niedermolekulares Heparin (NMH anstelle des üblichen Standardheparins verbucht werden (ASSENT PLUS Studie: t-PA + Dalteparin; HART-2-Studie: t-PA + Enoxaparin; ASSENT-3-Studie: TNK-tPA + Enoxaparin: In der ASSENT-3-Studie konnten die 30-Tages-Endpunkte (kombiniert in der TNK-tPA + Enoxaparin vs. der TNK-tPA + Standardheparin-Gruppe signifikant gesenkt werden (11,4 vs. 15,4 %; p kleiner 0,001. Zukünftige Entwicklungen: Derzeit sind Untersuchungen im Gange (ADVANCE-MI, ASSENT-4-PCI, FINESSE, die feststellen sollen, ob eine fixe Kombinationstherpie bestehend aus rasch verfügbarer medikamentöser Behandlung (Fibrinolyse, GP IIb/IIIa-Blocker oder Kombination aus beiden und einer unmittelbar nachfolgenden Optimierung des Koronarflusses mittels Akut-PCI in der Lage ist, die Mortalitätsrate von Reperfusionsmaßnahmen bei akutem STEMI ohne negative Beeinflussung der Blutungskomplikationsrate

  18. Des racines et des ailes

    Directory of Open Access Journals (Sweden)

    Stéphanie Vincent-Geslin

    2012-05-01

    Full Text Available Les mobilités pendulaires semblent être en augmentation en Europe depuis une dizaine d’années. Cette croissance du temps passé à se déplacer amène à remettre en question la conjecture de Zahavi et apparaît relativement inexplicable en regard du paradigme classique de l’acteur rationnel traditionnellement utilisé dans le champ des transports. Si, dans la littérature, les temps de déplacements sont principalement expliqués par le contexte résidentiel, la forme urbaine et le travail, ce cadre explicatif ne dit rien des processus de décision eux-mêmes qui amènent aux pendularités intensives.À partir d’une enquête qualitative menée auprès de pendulaires français, suisses et belges, cette contribution propose d’analyser les arbitrages et les éléments déterminants des processus de la grande pendularité. Les mobilités quotidiennes pendulaires apparaissent comme le résultat de compromis entre activité professionnelle, attachement résidentiel et choix de vie et prennent ainsi la forme de stratégies de conciliation entre vie privée et vie professionnelle. Ces mobilités spatiales permettent alors paradoxalement la préservation des ancrages résidentiels, sociaux et familiaux.Roots and wings. Long-distance commuting patterns, or how to conciliate professional and personal lifeLong-distance commuting patterns appear to be increasing in Europe over the last ten years. These raising mobility patterns lead to reappraise the Zahavi conjecture and appear largely inexplicable by the classical rational actor paradigm traditionally used in transportation research. In literature, commuting is mainly explained by residential contexts, urban forms and job. Nevertheless this theoretical frame says little about the decision-making processes themselves. Based on a qualitative survey conducted in three European countries - France, Belgium and Switzerland – among a population of high commuters, this paper proposes an analysis of

  19. Liste des contributeurs

    OpenAIRE

    2014-01-01

    Abouhani Abdelghani, Inau, Rabat. Blili Leïla, Université de La Manouba, Faculté des lettres, des arts et des humanités, La Manouba. Boubrik Rahal, Ihcc, Aix-en-Provence. Boujarra Hussein, Université de Tunis, Faculté des sciences humaines et sociales, Tunis/Diraset. Études maghrébines. Cattedra Raffaele, Université de Montpellier III. Catusse Myriam, Cnrs-Iremam, Aix-en-Provence. Cheraï Ahmed, École nationale d’administration, Rabat. Ettayeb Mahmoud, Université de Tunis, Faculté des sciences...

  20. Bioreactor and process design for biohydrogen production.

    Science.gov (United States)

    Show, Kuan-Yeow; Lee, Duu-Jong; Chang, Jo-Shu

    2011-09-01

    Biohydrogen is regarded as an attractive future clean energy carrier due to its high energy content and environmental-friendly conversion. It has the potential for renewable biofuel to replace current hydrogen production which rely heavily on fossil fuels. While biohydrogen production is still in the early stage of development, there have been a variety of laboratory- and pilot-scale systems developed with promising potential. This work presents a review of advances in bioreactor and bioprocess design for biohydrogen production. The state-of-the art of biohydrogen production is discussed emphasizing on production pathways, factors affecting biohydrogen production, as well as bioreactor configuration and operation. Challenges and prospects of biohydrogen production are also outlined.

  1. Filterability and Sludge Concentration in Membrane Bioreactors

    OpenAIRE

    Lousada-Ferreira, M

    2011-01-01

    The Thesis entitled “Filterability and Sludge Concentration in Membrane Bioreactors” aims at explaining the relation between Mixed Liquid Suspended Solids (MLSS) concentration, the amount of solids in the wastewater being treated, also designated as sludge, and filterability, being the ability of the sludge to be filtrated through a membrane, in a wastewater treatment system designated as Membrane Bioreactor (MBR). An MBR is a wastewater treatment system that combines an activated sludge proc...

  2. Anaerobic membrane bioreactors: Are membranes really necessary?

    OpenAIRE

    Davila, M.; Kassab, G.; Klapwijk, A.; Van, Lier, G

    2008-01-01

    Membranes themselves represent a significant cost for the full scale application of anaerobic membrane bioreactors (AnMBR). The possibility of operating an AnMBR with a self-forming dynamic membrane generated by the substances present in the reactor liquor would translate into an important saving. A self-forming dynamic membrane only requires a support material over which a cake layer is formed, which determines the rejection properties of the system. The present research studies the applicat...

  3. Engineering stem cell niches in bioreactors

    OpenAIRE

    2013-01-01

    Stem cells, including embryonic stem cells, induced pluripotent stem cells, mesenchymal stem cells and amniotic fluid stem cells have the potential to be expanded and differentiated into various cell types in the body. Efficient differentiation of stem cells with the desired tissue-specific function is critical for stem cell-based cell therapy, tissue engineering, drug discovery and disease modeling. Bioreactors provide a great platform to regulate the stem cell microenvironment, known as “ni...

  4. Oxygen transfer in a pressurized airlift bioreactor.

    Science.gov (United States)

    Campani, Gilson; Ribeiro, Marcelo Perencin Arruda; Horta, Antônio Carlos Luperni; Giordano, Roberto Campos; Badino, Alberto Colli; Zangirolami, Teresa Cristina

    2015-08-01

    Airlift bioreactors (ALBs) offer advantages over conventional systems, such as simplicity of construction, reduced risk of contamination, and efficient gas-liquid dispersion with low power consumption. ALBs are usually operated under atmospheric pressure. However, in bioprocesses with high oxygen demand, such as high cell density cultures, oxygen limitation may occur even when operating with high superficial gas velocity and air enriched with oxygen. One way of overcoming this drawback is to pressurize the reactor. In this configuration, it is important to assess the influence of bioreactor internal pressure on the gas hold-up, volumetric oxygen transfer coefficient (k(L)a), and volumetric oxygen transfer rate (OTR). Experiments were carried out in a concentric-tube airlift bioreactor with a 5 dm(3) working volume, equipped with a system for automatic monitoring and control of the pressure, temperature, and inlet gas flow rate. The results showed that, in disagreement with previous published results for bubble column and external loop airlift reactors, overpressure did not significantly affect k(L)a within the studied ranges of pressure (0.1-0.4 MPa) and superficial gas velocity in the riser (0.032-0.065 m s(-1)). Nevertheless, a positive effect on OTR was observed: it increased up to 5.4 times, surpassing by 2.3 times the oxygen transfer in a 4 dm(3) stirred tank reactor operated under standard cultivation conditions. These results contribute to the development of non-conventional reactors, especially pneumatic bioreactors operated using novel strategies for oxygen control.

  5. Bioreactor Yields Extracts for Skin Cream

    Science.gov (United States)

    2015-01-01

    Johnson Space Flight Center researchers created a unique rotating-wall bioreactor that simulates microgravity conditions, spurring innovations in drug development and medical research. Renuèll Int'l Inc., based in Aventure, Florida, licensed the technology and used it to produce a healing skin care product, RE`JUVEL. In a Food and Drug Administration test, RE`JUVEL substantially increased skin moisture and elasticity while reducing dark blotches and wrinkles.

  6. Nitrous oxides reduction pathways induced during nitrified leachate recirculation in bioreactor landfill; Voies de reduction des oxydes d'azote lors de leur injection dans un massif de dechets menagers et assimiles: contribution a l'etude de la recirculation de lixiviat nitrifie dans une installation de stockage de dechets menagers et assimiles bioactive

    Energy Technology Data Exchange (ETDEWEB)

    Vigneron, V.

    2005-12-15

    Nitrified leachate recirculation in bioreactor landfill has been proposed to avoid ammonium accumulation. We worked on the identification of nitrous oxides reduction pathways induced when nitrified leachate is recirculated during waste degradation. Batch reactors (1.1 liter, 40 g of reconstituted Municipal Solid Waste, MSW) were operated at 35 deg C and saturated with leachate. Injections of 250 mg N-NO{sub x}.10{sup -1} were performed during different phases of waste biodegradation. Nitrate reduction during acido-genic and active methanogenic phases, with an easily available carbon source in leachate, was mainly attributed to heterotrophic denitrification. However, H{sub 2}S concentration up to 0.7 % in the biogas (corresponding to 0.5 mmol of free H{sub 2}S per liter of leachate) led to prevalent DNRA (Dissimilatory Nitrate Reduction to Ammonium) over denitrification. This reaction hindered the release of nitrogen outside of the system. This observation was confirmed with experiments performed with {sup 15}N enriched nitrate. During late methanogenic phase, without any available carbon source in leachate, nitrate was reduced by autotrophic denitrification with sulfide as an electron donor. No free metal was detected in the leachate. N{sub 2}O transient accumulation was detected during both DNRA and autotrophic denitrification. A second set of experiments was conducted in a MSW pilot scale column (0.2 m{sup 3}, 80 kg of reconstituted waste) in methanogenic phase. 113 % and 203 % of nitrate were converted into N{sub 2} when a synthetic KNO{sub 3} solution (280 mg N.day{sup -1} during 77 days) or nitrified leachate (61 mg N.day{sup -1} during 54 days) were respectively injected into the system. The downward movement of a denitrification front passing through the waste mass was followed using 3 redox probes inserted at different levels of the pilot. Even if N{sub 2}O was never detected, a small production of this gas could not be totally excluded. It was established

  7. Degradation of Refuse in Hybrid Bioreactor Landfill

    Institute of Scientific and Technical Information of China (English)

    YAN LONG; Yu-YANG LONG; HAI-CHUN LIU; DONG-SHENG SHEN

    2009-01-01

    Objectivess To explore the process of refuse decomposition in hybrid bioreactor landfill. Methods The bioreactor landfill was operated in sequencing of facultative-anaerobic and aerobic conditions with leachate recireulation, pH, COD, and ammonia in the leachate and pH, biodegradable organic matter (BDM), and cation exchange capacity (CEC) in refuse were detected. Results CEC increased gradually with the degradation of refuse, which was negatively correlad, With BDM. COD and ammonia in the leachate was declined to 399.2 mg L-1 and 20.6 mg N L-1, respectively, during the 357-day operation. The respective concentrations of ammonia and COD were below the second and the third levels of current discharge standards in China. Conclusion The refuse is relatively stable at the end of hybrid bioreactor landfill operation. Most of the readily biodegradable organic matter is mineralized in the initial phase of refuse degradation, whereas the hard-biodegradable organic matter is mainly humidified in the maturity phase of refuse degradation.

  8. Replaceable Sensor System for Bioreactor Monitoring

    Science.gov (United States)

    Mayo, Mike; Savoy, Steve; Bruno, John

    2006-01-01

    A sensor system was proposed that would monitor spaceflight bioreactor parameters. Not only will this technology be invaluable in the space program for which it was developed, it will find applications in medical science and industrial laboratories as well. Using frequency-domain-based fluorescence lifetime technology, the sensor system will be able to detect changes in fluorescence lifetime quenching that results from displacement of fluorophorelabeled receptors bound to target ligands. This device will be used to monitor and regulate bioreactor parameters including glucose, pH, oxygen pressure (pO2), and carbon dioxide pressure (pCO2). Moreover, these biosensor fluorophore receptor-quenching complexes can be designed to further detect and monitor for potential biohazards, bioproducts, or bioimpurities. Biosensors used to detect biological fluid constituents have already been developed that employ a number of strategies, including invasive microelectrodes (e.g., dark electrodes), optical techniques including fluorescence, and membrane permeable systems based on osmotic pressure. Yet the longevity of any of these sensors does not meet the demands of extended use in spacecraft habitat or bioreactor monitoring. It was therefore necessary to develop a sensor platform that could determine not only fluid variables such as glucose concentration, pO2, pCO2, and pH but can also regulate these fluid variables with controlled feedback loop.

  9. Aujeszky's disease virus production in disposable bioreactor

    Indian Academy of Sciences (India)

    I Slivac; V Gaurina Srček; K Radošević; I Kmetič; Z Kniewald

    2006-09-01

    A novel, disposable-bag bioreactor system that uses wave action for mixing and transferring oxygen was evaluated for BHK 21 C13 cell line growth and Aujeszky’s disease virus (ADV) production. Growth kinetics of BHK 21 C13 cells in the wave bioreactor during 3-day period were determined. At the end of the 3-day culture period and cell density of 1.82 × 106 cells ml–1, the reactor was inoculated with 9 ml of gE- Bartha K-61 strain ADV suspension (105.9 TCID50) with multiplicity of infection (MOI) of 0.01. After a 144 h incubation period, 400 ml of ADV harvest was obtained with titre of 107.0 TCID50 ml–1, which corresponds to 40,000 doses of vaccine against AD. In conclusion, the results obtained with the wave bioreactor using BHK 21 C13 cells showed that this system can be considered as suitable for ADV or BHK 21 C13 cell biomass production.

  10. Denitrifying bioreactors for nitrate removal from tile drained cropland

    Science.gov (United States)

    Denitrification bioreactors are a promising technology for mitigation of nitrate-nitrogen (NO3-N) losses in subsurface drainage water. Bioreactors are constructed with carbon substrates, typically wood chips, to provide a substrate for denitrifying microorganisms. Researchers in Iowa found that for ...

  11. Microbial community analysis of a full-scale DEMON bioreactor.

    Science.gov (United States)

    Gonzalez-Martinez, Alejandro; Rodriguez-Sanchez, Alejandro; Muñoz-Palazon, Barbara; Garcia-Ruiz, Maria-Jesus; Osorio, Francisco; van Loosdrecht, Mark C M; Gonzalez-Lopez, Jesus

    2015-03-01

    Full-scale applications of autotrophic nitrogen removal technologies for the treatment of digested sludge liquor have proliferated during the last decade. Among these technologies, the aerobic/anoxic deammonification process (DEMON) is one of the major applied processes. This technology achieves nitrogen removal from wastewater through anammox metabolism inside a single bioreactor due to alternating cycles of aeration. To date, microbial community composition of full-scale DEMON bioreactors have never been reported. In this study, bacterial community structure of a full-scale DEMON bioreactor located at the Apeldoorn wastewater treatment plant was analyzed using pyrosequencing. This technique provided a higher-resolution study of the bacterial assemblage of the system compared to other techniques used in lab-scale DEMON bioreactors. Results showed that the DEMON bioreactor was a complex ecosystem where ammonium oxidizing bacteria, anammox bacteria and many other bacterial phylotypes coexist. The potential ecological role of all phylotypes found was discussed. Thus, metagenomic analysis through pyrosequencing offered new perspectives over the functioning of the DEMON bioreactor by exhaustive identification of microorganisms, which play a key role in the performance of bioreactors. In this way, pyrosequencing has been proven as a helpful tool for the in-depth investigation of the functioning of bioreactors at microbiological scale.

  12. Sulfur formation and recovery in a thiosulfateoxidizing bioreactor

    NARCIS (Netherlands)

    Gonzalez-Sanchez, A.; Meulepas, R.J.W.; Revah, S.

    2008-01-01

    This work describes the design and Performance of a thiosulfate-oxidizing bioreactor that allowed high elemental sulfur production and recovery efficiency. The reactor system, referred to as a Supernatant-Recycling Settler Bioreactor (SRSB), consisted of a cylindrical upflow reactor and a separate a

  13. Evaluation of woodchip bioreactors for improved water quality

    Science.gov (United States)

    Woodchip bioreactors are gaining popularity with farmers because of their edge-of-field nitrate removal capabilities, which do not require changes in land management practices. However, limited research has been conducted to study the potential of these bioreactors to also reduce downstream transpor...

  14. Anatomie et identification des bois

    OpenAIRE

    Jourez, Benoît

    2010-01-01

    Anatomie des bois Structure anatomique des résineux et des feuillus Structure de la membrane cellulaire structure submicroscopique Anatomie du bois des essences feuillues tropicales Caractères anatomiques servant à l'identification des essences Reconnaissance microscopique du bois des essences résineuses et feuillues Duramen et duraminisation Formations anormales ( bois de compression et bois de tension) Chimie du bois Composition générale Cellulose, hé...

  15. Groupement des faits

    OpenAIRE

    Langlois, Charles-Victor; Seignobos, Charles

    2014-01-01

    I. La première nécessité qui s’impose à l’historien mis en présence du chaos des faits historiques, c’est de limiter son champ de recherches. Dans l’océan de l’histoire universelle quels faits choisira-t-il pour les recueillir ? – Puis, dans la masse des faits ainsi choisis, il lui faudra distinguer des groupes et faire des sections. – Enfin dans chacune de ces sections il aura à ranger les faits un à un. Ainsi toute construction historique doit commencer par trouver un principe pour trier, e...

  16. STATE OF THE PRACTICE FOR BIOREACTOR LANDFILLS - SUMMARY OF USEPA WORKSHOP ON BIOREACTOR LANDFILLS: SUMMARY

    Science.gov (United States)

    This is a summary of the Workshop on Landfill Bioreactors, held 9/6-7/2000 in Arlington, VA. The purpose of the workshop was to provide a forum to EPA, state and local governments, solid waste industry, and academic research representatives to exchange information and ideas on b...

  17. Disposable bioreactors for inoculum production and protein expression.

    Science.gov (United States)

    Eibl, Regine; Löffelholz, Christian; Eibl, Dieter

    2014-01-01

    Disposable bioreactors have been increasingly implemented over the past ten years. This relates to both R & D and commercial manufacture, in particular, in animal cell-based processes. Among the numerous disposable bioreactors which are available today, wave-mixed bag bioreactors and stirred bioreactors are predominant. Whereas wave-mixed bag bioreactors represent the system of choice for inoculum production, stirred systems are often preferred for protein expression. For this reason, the authors present protocols instructing the reader how to use the wave-mixed BIOSTAT CultiBag RM 20 L for inoculum production and the stirred UniVessel SU 2 L for recombinant protein production at benchtop scale. All methods described are based on a Chinese hamster ovary (CHO) suspension cell line expressing the human placental secreted alkaline phosphatase (SEAP).

  18. Gestion des risques

    CERN Document Server

    Louisot, Jean-Paul

    2009-01-01

    Depuis le début du lie siècle, la gestion des risques connaît une véritable révolution culturelle. Jusqu'alors fonction technique, centrée autour de l'achat de couverture d'assurances, elle est devenue une discipline managériale et transversale : une valise d'instruments que chaque manager doit connaître et appliquer quels que soient son domaine de compétence et ses missions au sein de l'organisation. En effet, la gestion des risques est une culture qui doit être assimilée par chacun des acteurs. C'est précisément l'ambition des 101 questions rassemblées dans cet ouvrage : apporter à chaque manager d'entreprise, de collectivité, d'établissement de santé..., des réponses claires au " pourquoi " et au " comment " : Comment identifier les risques ? Comment analyser les risques ? Quels sont les objectifs de la gestion des risques ? Une carte des risques pour quoi faire ? Pourquoi faut-il financer les risques ? Les entreprises ont-elles des responsabilités pénales ? En quoi consiste la gestion...

  19. Disposable polymeric cryogel bioreactor matrix for therapeutic protein production.

    Science.gov (United States)

    Jain, Era; Kumar, Ashok

    2013-05-01

    Low cost and high efficiency make disposable bioreactors feasible for small-scale therapeutic development and initial clinical trials. We have developed a cryogel-based disposable bioreactor matrix, which has been used for production of protein therapeutics such as urokinase and monoclonal antibodies (mAbs). The protocol discusses the application of a cryogel bioreactor for mAb production. Cryogels composed of either polyacrylamide (PAAm) coupled to gelatin or semi-interpenetrating PAAm-chitosan are synthesized by free-radical polymerization at -12 °C. Hybridoma cells are immobilized over the cryogel bioreactor and incubated for 48 h. Medium is circulated thereafter at 0.2 ml min(-1) and bioreactors can be run continuously for 60 d. The cryogel-based packed-bed bioreactor can be formulated as a monolith or as beads; it also has an efficiency four times what can be obtained using a tissue-culture flask, a high surface-to-volume ratio and effective nutrient transport. After incubation, the bioreactor setup will take about 60 min using a pre-prepared sterilized cryogel.

  20. Disposable Bioreactors for Plant Micropropagation and Mass Plant Cell Culture

    Science.gov (United States)

    Ducos, Jean-Paul; Terrier, Bénédicte; Courtois, Didier

    Different types of bioreactors are used at Nestlé R&D Centre - Tours for mass propagation of selected plant varieties by somatic embryogenesis and for large scale culture of plants cells to produce metabolites or recombinant proteins. Recent studies have been directed to cut down the production costs of these two processes by developing disposable cell culture systems. Vegetative propagation of elite plant varieties is achieved through somatic embryogenesis in liquid medium. A pilot scale process has recently been set up for the industrial propagation of Coffea canephora (Robusta coffee). The current production capacity is 3.0 million embryos per year. The pre-germination of the embryos was previously conducted by temporary immersion in liquid medium in 10-L glass bioreactors. An improved process has been developed using a 10-L disposable bioreactor consisting of a bag containing a rigid plastic box ('Box-in-Bag' bioreactor), insuring, amongst other advantages, a higher light transmittance to the biomass due to its horizontal design. For large scale cell culture, two novel flexible plastic-based disposable bioreactors have been developed from 10 to 100 L working volumes, validated with several plant species ('Wave and Undertow' and 'Slug Bubble' bioreactors). The advantages and the limits of these new types of bioreactor are discussed, based mainly on our own experience on coffee somatic embryogenesis and mass cell culture of soya and tobacco.

  1. Landfill leachate treatment in assisted landfill bioreactor

    Institute of Scientific and Technical Information of China (English)

    HE Pin-jing; QU Xian; SHAO Li-ming; LEE Duu-jong

    2006-01-01

    Landfill is the major disposal route of municipal solid waste(MSW) in most Asian countries. Leachate from landfill presents a strong wastewater that needs intensive treatment before discharge. Direct recycling was proposed as an effective alternative for leachate treatment by taking the landfill as a bioreactor. This process was proved not only considerably reducing the pollution potential of leachate, but also enhancing organic degradation in the landfill. However, as this paper shows, although direct leachate recycling was effective in landfilled MSW with low food waste fraction (3.5%, w/w), it failed in MSW containing 54% food waste, as normally noted in Asian countries. The initial acid stuck would inhibit methanogenesis to build up, hence strong leachate was yielded from landfill to threaten the quality of receiving water body. We demonstrated the feasibility to use an assisted bioreactor landfill, with a well-decomposed refuse layer as ex-situ anaerobic digester to reducing COD loading in leachate. By doing so, the refuse in simulated landfill column (2.3 m high) could be stabilized in 30 weeks while the COD in leachate reduced by 95%(61000 mg/L to 3000 mg/L). Meanwhile, the biogas production was considerably enhanced, signaling by the much greater amount and much higher methane content in the biogas.

  2. MEMBRANE BIOREACTOR FOR TREATMENT OF RECALCITRANT WASTEWATERS

    Directory of Open Access Journals (Sweden)

    Suprihatin Suprihatin

    2012-02-01

    Full Text Available The low biodegradable wastewaters remain a challenge in wastewater treatment technology. The performance of membrane bioreactor systems with submerged hollow fiber micro- and ultrafiltration membrane modules were examined for purifying recalcitrant wastewaters of leachate of a municipal solid waste open dumping site and effluent of pulp and paper mill. The use of MF and UF membrane bioreactor systems showed an efficient treatment for both types wastewaters with COD reduction of 80-90%. The membrane process achieved the desirable effects of maintaining reasonably high biomass concentration and long sludge retention time, while producing a colloid or particle free effluent. For pulp and paper mill effluent a specific sludge production of 0.11 kg MLSS/kg COD removed was achieved. A permeate flux of about 5 L/m²h could be achieved with the submerged microfiltration membrane. Experiments using ultrafiltration membrane produced relatively low permeate fluxes of 2 L/m²h. By applying periodical backwash, the flux could be improved significantly. It was indicated that the particle or colloid deposition on membrane surface was suppressed by backwash, but reformation of deposit was not effectively be prevented by shear-rate effect of aeration. Particle and colloid started to accumulate soon after backwash. Construction of membrane module and operation mode played a critical role in achieving the effectiveness of aeration in minimizing deposit formation on the membrane surface.

  3. Membrane bioreactor for drinking water denitrification

    Energy Technology Data Exchange (ETDEWEB)

    Barreiros, A.M. [Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa (Portugal)]|[Escola Superior de Tecnologia, Instituto Politecnico de Setubal, Rua do Vale de Chaves, Estefanilha, 2900 Setubal (Portugal); Rodrigues, C.M.; Crespo, J.P.S.G.; Reis, M.A.M. [Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa (Portugal)

    1998-04-01

    The aim of this study is to evaluate the performance of a membrane bioreactor with cell recycle to be used for drinking water denitrification, when operated with a high nitrate load (up to 7.68 kgNO{sub 3}{sup -}/m{sup 3} day) and low hydraulic retention time (down to 0.625 h). Nitrate and nitrite were always completely removed for all the operational conditions used. The effluent`s nitrite concentration kept below 0.1 mg NO{sub 2}{sup -}/l with exception of a short period, during the reactor start-up, when it accumulates. The performance of the membrane bioreactor was also evaluated using a groundwater containing 148 mg NO{sub 3}{sup -}/l. Nitrate and nitrite concentration in the effluent were below the recommended values for drinking water when the reactor was controlled at pH 7.0. The membrane flux decreases during operation as a consequence of membrane fouling. The flux decrease was more severe during operation with synthetic medium than with contaminated groundwater due to the existence of molecular complexes in the synthetic broth. A backshock technique was used to reduce the surface fouling of the membrane. Combining this technique with the use of a reserve asymmetric structured membrane it was found that the membrane flux remains nearly unchanged. (orig.) With 7 figs., 14 refs.

  4. Novel Hydrogen Bioreactor and Detection Apparatus.

    Science.gov (United States)

    Rollin, Joseph A; Ye, Xinhao; Del Campo, Julia Martin; Adams, Michael W W; Zhang, Y-H Percival

    2016-01-01

    In vitro hydrogen generation represents a clear opportunity for novel bioreactor and system design. Hydrogen, already a globally important commodity chemical, has the potential to become the dominant transportation fuel of the future. Technologies such as in vitro synthetic pathway biotransformation (SyPaB)-the use of more than 10 purified enzymes to catalyze unnatural catabolic pathways-enable the storage of hydrogen in the form of carbohydrates. Biohydrogen production from local carbohydrate resources offers a solution to the most pressing challenges to vehicular and bioenergy uses: small-size distributed production, minimization of CO2 emissions, and potential low cost, driven by high yield and volumetric productivity. In this study, we introduce a novel bioreactor that provides the oxygen-free gas phase necessary for enzymatic hydrogen generation while regulating temperature and reactor volume. A variety of techniques are currently used for laboratory detection of biohydrogen, but the most information is provided by a continuous low-cost hydrogen sensor. Most such systems currently use electrolysis for calibration; here an alternative method, flow calibration, is introduced. This system is further demonstrated here with the conversion of glucose to hydrogen at a high rate, and the production of hydrogen from glucose 6-phosphate at a greatly increased reaction rate, 157 mmol/L/h at 60 °C. PMID:25022362

  5. Landfill leachate treatment in assisted landfill bioreactor.

    Science.gov (United States)

    He, Pin-Jing; Qu, Xian; Shao, Li-Ming; Lee, Duu-Jong

    2006-01-01

    Landfill is the major disposal route of municipal solid waste (MSW) in most Asian countries. Leachate from landfill presents a strong wastewater that needs intensive treatment before discharge. Direct recycling was proposed as an effective alternative for leachate treatment by taking the landfill as a bioreactor. This process was proved not only considerably reducing the pollution potential of leachate, but also enhancing organic degradation in the landfill. However, as this paper shows, although direct leachate recycling was effective in landfilled MSW with low food waste fraction (3.5%, w/w), it failed in MSW containing 54% food waste, as normally noted in Asian countries. The initial acid stuck would inhibit methanogenesis to build up, hence strong leachate was yielded from landfill to threaten the quality of receiving water body. We demonstrated the feasibility to use an assisted bioreactor landfill, with a well-decomposed refuse layer as ex-situ anaerobic digester to reducing COD loading in leachate. By doing so, the refuse in simulated landfill column (2.3 m high) could be stabilized in 30 weeks while the COD in leachate reduced by 95% (61000 mg/L to 3000 mg/L). Meanwhile, the biogas production was considerably enhanced, signaling by the much greater amount and much higher methane content in the biogas. PMID:20050569

  6. LTCC based bioreactors for cell cultivation

    Science.gov (United States)

    Bartsch, H.; Welker, T.; Welker, K.; Witte, H.; Müller, J.

    2016-01-01

    LTCC multilayers offer a wide range of structural options and flexibility of connections not available in standard thin film technology. Therefore they are considered as material base for cell culture reactors. The integration of microfluidic handling systems and features for optical and electrical capturing of indicators for cell culture growth offers the platform for an open system concept. The present paper assesses different approaches for the creation of microfluidic channels in LTCC multilayers. Basic functions required for the fluid management in bioreactors include temperature and flow control. Both features can be realized with integrated heaters and temperature sensors in LTCC multilayers. Technological conditions for the integration of such elements into bioreactors are analysed. The temperature regulation for the system makes use of NTC thermistor sensors which serve as real value input for the control of the heater. It allows the adjustment of the fluid temperature with an accuracy of 0.2 K. The tempered fluid flows through the cell culture chamber. Inside of this chamber a thick film electrode array monitors the impedance as an indicator for the growth process of 3-dimensional cell cultures. At the system output a flow sensor is arranged to monitor the continual flow. For this purpose a calorimetric sensor is implemented, and its crucial design parameters are discussed. Thus, the work presented gives an overview on the current status of LTCC based fluid management for cell culture reactors, which provides a promising base for the automation of cell culture processes.

  7. Novel Hydrogen Bioreactor and Detection Apparatus.

    Science.gov (United States)

    Rollin, Joseph A; Ye, Xinhao; Del Campo, Julia Martin; Adams, Michael W W; Zhang, Y-H Percival

    2016-01-01

    In vitro hydrogen generation represents a clear opportunity for novel bioreactor and system design. Hydrogen, already a globally important commodity chemical, has the potential to become the dominant transportation fuel of the future. Technologies such as in vitro synthetic pathway biotransformation (SyPaB)-the use of more than 10 purified enzymes to catalyze unnatural catabolic pathways-enable the storage of hydrogen in the form of carbohydrates. Biohydrogen production from local carbohydrate resources offers a solution to the most pressing challenges to vehicular and bioenergy uses: small-size distributed production, minimization of CO2 emissions, and potential low cost, driven by high yield and volumetric productivity. In this study, we introduce a novel bioreactor that provides the oxygen-free gas phase necessary for enzymatic hydrogen generation while regulating temperature and reactor volume. A variety of techniques are currently used for laboratory detection of biohydrogen, but the most information is provided by a continuous low-cost hydrogen sensor. Most such systems currently use electrolysis for calibration; here an alternative method, flow calibration, is introduced. This system is further demonstrated here with the conversion of glucose to hydrogen at a high rate, and the production of hydrogen from glucose 6-phosphate at a greatly increased reaction rate, 157 mmol/L/h at 60 °C.

  8. Negative Effects of Sludge Bulking in Membrane Bio-Reactor

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying; HUANG Zhi; REN Nanqi; MENG Qingjuan

    2006-01-01

    Sludge bulking property of membrane bio-reactor was investigated in this study through contrast research. When the sludge bulking appeared, the removal efficiency of COD in membrane bio-reactor increased slightly through the function of filamentous bacteria. However, the negative effects of the higher net water-head differential pressures, the high block rate of membrane pore and the great quantity of filamentous bacteria at the external surface presented at the same time. Thus, plenty of methods should be performed to control sludge bulking once it happened in membrane bio-reactor.

  9. Photonique des Morphos

    CERN Document Server

    Berthier, Serge

    2010-01-01

    La photonique est déjà présente dans notre vie quotidienne, et on attend maintenant que la manipulation des photons permette aussi le traitement logique des informations. Cependant, l’élément de base qui permet cette manipulation de la lumière, le cristal photonique, est d’une réalisation complexe et mal contrôlée. Dans la course à la maîtrise de la lumière, les structures photoniques naturelles ont beaucoup à nous apprendre. C’est ce que nous montre Serge Berthier qui étudie dans ce livre la structure des écailles des Morphos. Tenant compte de l’essor récent des approches biomimétiques, il présente de manière détaillée plus de dix-huit techniques expérimentales utilisées pour ses analyses, ainsi que les diverses approches théoriques développées pour la modélisation de structures multi-échelles complexes. Première étude quasi-exhaustive des structures fines d’un genre et des propriétés optiques ainsi que colorimétriques générées, ce livre fournit aux entomologiste...

  10. Droit des organisations internationales

    CERN Document Server

    Sorel, Jean-Marc; Ndior, Valère

    2013-01-01

    Cet ouvrage collectif offre aux enseignants et chercheurs en droit international, aux praticiens et aux étudiants, une analyse actualisée du droit des organisations internationales. Il dresse en cinq parties un tableau, illustré par des exemples variés, des problématiques que soulève le phénomène polymorphe d institutionnalisation de la société internationale. La première partie est consacrée au phénomène des « organisations internationales », sous l angle à la fois de l institutionnalisation progressive des relations internationales et de la difficulté à cerner une catégorie unifiée. La deuxième partie rend compte de la création, de la disparition et des mutations des organisations internationales, ici envisagées comme systèmes institutionnels et ordres juridiques dérivés. La troisième partie analyse l autonomie que l acquisition de la personnalité juridique et de privilèges et immunités, un organe administratif intégré, un personnel ou un budget propres confèrent aux organi...

  11. Mechanobiologic Research in a Microgravity Environment Bioreactor

    Science.gov (United States)

    Guidi, A.; Dubini, G.; Tominetti, F.; Raimondi, M.

    A current problem in tissue culturing technology is the unavailability of an effective Bioreactor for the in vitro cultivation of cells and explants. It has, in fact, proved extremely difficult to promote the high-density three-dimensional in vitro growth of human tissues that have been removed from the body and deprived of their normal in vivo vascular sources of nutrients and gas exchange. A variety of tissue explants can be maintained for a short period of time on a supportive collagen matrix surrounded by culture medium. But this system provides only limited mass transfer of nutrients and wastes through the tissue, and gravity-induced sedimentation prevents complete three- dimensional cell-cell and cell-matrix interactions. Several devices presently on the market have been used with only limited success since each has limitations, which restrict usefulness and versatility. Further, no Bioreactor or culture vessel is known that will allow for unimpeded growth of three dimensional cellular aggregates or tissue. Extensive research on the effect of mechanical stimuli on cell metabolism suggests that tissues may respond to mechanical stimulation via loading-induced flow of the interstitial fluids. During the culture, cells are subject to a flow of culture medium. Flow properties such as flow field, flow regime (e.g. turbulent or laminar), flow pattern (e.g. circular), entity and distribution of the shear stress acting on the cells greatly influence fundamental aspects of cell function, such as regulation and gene expression. This has been demonstrated for endothelial cells and significant research efforts are underway to elucidate these mechanisms in various other biological systems. Local fluid dynamics is also responsible of the mass transfer of nutrients and catabolites as well as oxygenation through the tissue. Most of the attempts to culture tissue-engineered constructs in vitro have utilized either stationary cultures or systems generating relatively small

  12. Des femmes au tribunal

    OpenAIRE

    Le Pape, Marc

    2010-01-01

    Les archives judiciaires constituent une source essentielle pour les études des sociabilités africaines en situation coloniale. Cet article prend appui sur l’analyse des procès tenus, entre 1923 et 1939, au tribunal du premier degré d’Abidjan, il vise à décrire les argumentations contradictoires par lesquelles femmes et hommes expliquent leurs différends dans l’espace du prétoire. Les registres issus des « juridictions indigènes » permettent également d’apprécier sur quels repères se fondent ...

  13. Des ballons pour demain

    Science.gov (United States)

    Régipa, R.

    A partir d'une théorie sur la détermination des formes et des contraintes globales d'un ballon de révolution, ou s'en rapprochant, une nouvelle famille de ballons a été définie. Les ballons actuels, dits de ``forme naturelle'', sont calculés en général pour une tension circonférencielle nulle. Ainsi, pour une mission donnée, la tension longitudinale et la forme de l'enveloppe sont strictement imposées. Les ballons de la nouvelle génération sont globalement cylindriques et leurs pôles sont réunis par un câble axial, chargé de transmettre une partie des efforts depuis le crochet (pôle inférieur), directement au pôle supérieur. De plus, la zone latérale cylindrique est soumise à un faible champ de tensions circonférencielles. Ainsi, deux paramètres permettent de faire évoluer la distribution des tensions et la forme de l'enveloppe: - la tension du câble de liaison entre pôles (ou la longueur de ce câble) - la tension circonférencielle moyenne désirée (ou le rayon du ballon). On peut donc calculer et réaliser: - soit des ballons de forme adaptée, comme les ballons à fond plat pour le bon fonctionnement des montgolfières infrarouge (projet MIR); - soit des ballons optimisés pour une bonne répartition des contraintes et une meilleure utilisation des matériaux d'enveloppe, pour l'ensemble des programmes stratosphériques. Il s'ensuit une économie sensible des coûts de fabrication, une fiabilité accrue du fonctionnement de ces ballons et une rendement opérationnel bien supérieur, permettant entre autres, d'envisager des vols à très haute altitude en matériaux très légers.

  14. Liste des auteurs

    OpenAIRE

    2014-01-01

    Abdoul Razack Adjibi-Oualiou, agronome forestierdirection des Forêts et des Ressources naturellesBP 393, Cotonou, république du Béninmailto: Aristide Cossi Adomou, botanisteuniversité d’Abomey-Calavi, faculté des Sciences et Techniques département de Biologie végétaleHerbier national du Bénin, 01 BP 4521, Cotonou, république du Béninmailto: Pierre Onodjè Agbani, botaniste systématicien, écologuelaboratoire d'Écologie appliquée, Cotonou, république du B...

  15. Les savoirs des autres

    OpenAIRE

    Bromberger, Christian

    2007-01-01

    En ethnologie, comme dans bien d'autres domaines scientifiques, le renouvellement des problématiques est souvent venu des confins territoriaux, de points marginaux de rencontre entre disciplines voisines. Chacun de ces rendez-vous marque une étape importante dans l'histoire de la démarche ethnologique ; le dialogue qui s'est noué avec la technologie, la linguistique et la sémiologie, les sciences naturelles, la médecine... a permis non seulement une extension du champ et un affinement des mét...

  16. Abhängigkeit von Addukten tabakspezifischer Nitrosamine in der Mundschleimhaut des Menschen von verschiedenen Genussformen des Tabaks, ihre Beeinflussung durch Ernährung, Alkohol und Chemopräventiva und die Überprüfung der Effekte an der Ratte

    OpenAIRE

    Heling, Anne-Kathrin

    2009-01-01

    Das Oropharynxkarzinom steht in Deutschland mit einem Anteil von 3,3% an allen bösartigen Neubil¬dungen bei Männern an der siebten Stelle der Krebsneuerkrankungen. Der jahrelange Gebrauch von Tabakwaren ist ein wichtiger Risikofaktor, der durch gleichzeitige Anwendung hochprozentiger Alko¬holika multipliziert wird. In vielen westeuropäischen Industrieländern konnte eine Zunahme von Inzi¬denz und Mortalität festgestellt werden, dagegen weist Schweden die niedrigste Inzidenzrate auf. Eine mögli...

  17. Bioreactors Drive Advances in Tissue Engineering

    Science.gov (United States)

    2012-01-01

    It was an unlikely moment for inspiration. Engineers David Wolf and Ray Schwarz stopped by their lab around midday. Wolf, of Johnson Space Center, and Schwarz, with NASA contractor Krug Life Sciences (now Wyle Laboratories Inc.), were part of a team tasked with developing a unique technology with the potential to enhance medical research. But that wasn t the focus at the moment: The pair was rounding up colleagues interested in grabbing some lunch. One of the lab s other Krug engineers, Tinh Trinh, was doing something that made Wolf forget about food. Trinh was toying with an electric drill. He had stuck the barrel of a syringe on the bit; it spun with a high-pitched whirr when he squeezed the drill s trigger. At the time, a multidisciplinary team of engineers and biologists including Wolf, Schwarz, Trinh, and project manager Charles D. Anderson, who formerly led the recovery of the Apollo capsules after splashdown and now worked for Krug was pursuing the development of a technology called a bioreactor, a cylindrical device used to culture human cells. The team s immediate goal was to grow human kidney cells to produce erythropoietin, a hormone that regulates red blood cell production and can be used to treat anemia. But there was a major barrier to the technology s success: Moving the liquid growth media to keep it from stagnating resulted in turbulent conditions that damaged the delicate cells, causing them to quickly die. The team was looking forward to testing the bioreactor in space, hoping the device would perform more effectively in microgravity. But on January 28, 1986, the Space Shuttle Challenger broke apart shortly after launch, killing its seven crewmembers. The subsequent grounding of the shuttle fleet had left researchers with no access to space, and thus no way to study the effects of microgravity on human cells. As Wolf looked from Trinh s syringe-capped drill to where the bioreactor sat on a workbench, he suddenly saw a possible solution to both

  18. EMERGING TECHNOLOGY BULLETIN - METHANOTROPHIC BIOREACTOR SYSTEM - BIOTROL, INC.

    Science.gov (United States)

    BioTrol's Methanotrophic Bioreactor is an above-ground remedial system for water contaminated with halogenated volatile organic compounds, including trichloroethylene (ICE) and related chemicals. Its design features circumvent problems peculiar to treatment of this unique class o...

  19. Production of monoclonal antibody with Celline-350 bioreactor

    International Nuclear Information System (INIS)

    Monoclonal antibodies are protein that are highly specific and sensitive in their reaction with specific sites on target molecules that they have become reagents of central importance in the diagnostic and treatment of human diseases. This paper reports the use of CELLine-350 bioreactor to produce continuous supply of serum-free breast cancer monoclonal antibody. Initial volume of 5ml (1.5 x 106 viable cells/ml) is inoculated into the bioreactor and harvesting is done every 5 days to obtain high yield monoclonal antibody. The serum-free supernatant is precipitated with 50% saturated ammonia sulfate and the antibody is purified by protein-G affinity chromatography. The concentration of monoclonal antibody successfully produced by the bioreactor is 0.91mg/ml respectively and it is measured by the Lowry method. This result shows that bioreactor Celline-350 is easy to handle and cost effective for the continuous production of serum free monoclonal antibody. (Author)

  20. The Potential for Microalgae as Bioreactors to Produce Pharmaceuticals

    Science.gov (United States)

    Yan, Na; Fan, Chengming; Chen, Yuhong; Hu, Zanmin

    2016-01-01

    As photosynthetic organisms, microalgae can efficiently convert solar energy into biomass. Microalgae are currently used as an important source of valuable natural biologically active molecules, such as carotenoids, chlorophyll, long-chain polyunsaturated fatty acids, phycobiliproteins, carotenoids and enzymes. Significant advances have been achieved in microalgae biotechnology over the last decade, and the use of microalgae as bioreactors for expressing recombinant proteins is receiving increased interest. Compared with the bioreactor systems that are currently in use, microalgae may be an attractive alternative for the production of pharmaceuticals, recombinant proteins and other valuable products. Products synthesized via the genetic engineering of microalgae include vaccines, antibodies, enzymes, blood-clotting factors, immune regulators, growth factors, hormones, and other valuable products, such as the anticancer agent Taxol. In this paper, we briefly compare the currently used bioreactor systems, summarize the progress in genetic engineering of microalgae, and discuss the potential for microalgae as bioreactors to produce pharmaceuticals. PMID:27322258

  1. Hairy root culture: bioreactor design and process intensification.

    Science.gov (United States)

    Stiles, Amanda R; Liu, Chun-Zhao

    2013-01-01

    The cultivation of hairy roots for the production of secondary metabolites offers numerous advantages; hairy roots have a fast growth rate, are genetically stable, and are relatively simple to maintain in phytohormone free media. Hairy roots provide a continuous source of secondary metabolites, and are useful for the production of chemicals for pharmaceuticals, cosmetics, and food additives. In order for hairy roots to be utilized on a commercial scale, it is necessary to scale-up their production. Over the last several decades, significant research has been conducted on the cultivation of hairy roots in various types of bioreactor systems. In this review, we discuss the advantages and disadvantages of various bioreactor systems, the major factors related to large-scale bioreactor cultures, process intensification technologies and overview the mathematical models and computer-aided methods that have been utilized for bioreactor design and development.

  2. Bioreactor activated graft material for early implant fixation in bone

    DEFF Research Database (Denmark)

    Snoek Henriksen, Susan; Ding, Ming; Overgaard, Søren

    2011-01-01

    Introduction The combined incubation of a composite scaffold with bone marrow stromal cells in a perfusion bioreactor could make up a novel hybrid graft material with optimal properties for early fixation of implant to bone. The aim of this study was to create a bioreactor activated graft (BAG......) material, which could induce early implant fixation similar to that of allograft. Two porous scaffold materials incubated with cells in a perfusion bioreactor were tested in this study. Methods and Materials Two groups of 8 skeletally mature female sheep were anaesthetized before aspiration of bone marrow...... from the iliac crest. For both groups, mononuclear cells were isolated, and injected into a perfusion bioreactor (Millenium Biologix AG, Switzerland). Scaffold granules (Ø~900-1500 µm, ~88% porosity) in group 1, consisted of hydroxyapatite (HA, 70%) with β-tricalcium-phosphate (β-TCP, 30%) (Danish...

  3. Modelling across bioreactor scales: methods, challenges and limitations

    DEFF Research Database (Denmark)

    Gernaey, Krist

    Scale-up and scale-down of bioreactors are very important in industrial biotechnology, especially with the currently available knowledge on the occurrence of gradients in industrial-scale bioreactors. Moreover, it becomes increasingly appealing to model such industrial scale systems, considering...... that it is challenging and expensive to acquire experimental data of good quality that can be used for characterizing gradients occurring inside a large industrial scale bioreactor. But which model building methods are available? And how can one ensure that the parameters in such a model are properly estimated? And what...... are the limitations of different types of mod - els? This paper will provide examples of models that have been published in the literature for use across bioreactor scales, including computational fluid dynamics (CFD) and population balance models. Furthermore, the importance of good modeling practice...

  4. Upflow bioreactor with septum and pressure release mechanism

    Science.gov (United States)

    Hansen, Conly L.; Hansen, Carl S.; Pack, Kevin; Milligan, John; Benefiel, Bradley C.; Tolman, C. Wayne; Tolman, Kenneth W.

    2010-04-20

    An upflow bioreactor includes a vessel having an inlet and an outlet configured for upflow operation. A septum is positioned within the vessel and defines a lower chamber and an upper chamber. The septum includes an aperture that provides fluid communication between the upper chamber and lower chamber. The bioreactor also includes means for releasing pressure buildup in the lower chamber. In one configuration, the septum includes a releasable portion having an open position and a closed position. The releasable portion is configured to move to the open position in response to pressure buildup in the lower chamber. In the open position fluid communication between the lower chamber and the upper chamber is increased. Alternatively the lower chamber can include a pressure release line that is selectively actuated by pressure buildup. The pressure release mechanism can prevent the bioreactor from plugging and/or prevent catastrophic damage to the bioreactor caused by high pressures.

  5. The Potential for Microalgae as Bioreactors to Produce Pharmaceuticals.

    Science.gov (United States)

    Yan, Na; Fan, Chengming; Chen, Yuhong; Hu, Zanmin

    2016-01-01

    As photosynthetic organisms, microalgae can efficiently convert solar energy into biomass. Microalgae are currently used as an important source of valuable natural biologically active molecules, such as carotenoids, chlorophyll, long-chain polyunsaturated fatty acids, phycobiliproteins, carotenoids and enzymes. Significant advances have been achieved in microalgae biotechnology over the last decade, and the use of microalgae as bioreactors for expressing recombinant proteins is receiving increased interest. Compared with the bioreactor systems that are currently in use, microalgae may be an attractive alternative for the production of pharmaceuticals, recombinant proteins and other valuable products. Products synthesized via the genetic engineering of microalgae include vaccines, antibodies, enzymes, blood-clotting factors, immune regulators, growth factors, hormones, and other valuable products, such as the anticancer agent Taxol. In this paper, we briefly compare the currently used bioreactor systems, summarize the progress in genetic engineering of microalgae, and discuss the potential for microalgae as bioreactors to produce pharmaceuticals. PMID:27322258

  6. Hairy root culture: bioreactor design and process intensification.

    Science.gov (United States)

    Stiles, Amanda R; Liu, Chun-Zhao

    2013-01-01

    The cultivation of hairy roots for the production of secondary metabolites offers numerous advantages; hairy roots have a fast growth rate, are genetically stable, and are relatively simple to maintain in phytohormone free media. Hairy roots provide a continuous source of secondary metabolites, and are useful for the production of chemicals for pharmaceuticals, cosmetics, and food additives. In order for hairy roots to be utilized on a commercial scale, it is necessary to scale-up their production. Over the last several decades, significant research has been conducted on the cultivation of hairy roots in various types of bioreactor systems. In this review, we discuss the advantages and disadvantages of various bioreactor systems, the major factors related to large-scale bioreactor cultures, process intensification technologies and overview the mathematical models and computer-aided methods that have been utilized for bioreactor design and development. PMID:23604206

  7. Microbial Bioreactor Development in the ALS NSCORT

    Science.gov (United States)

    Mitchell, Cary; Whitaker, Dawn; Banks, M. Katherine; Heber, Albert J.; Turco, Ronald F.; Nies, Loring F.; Alleman, James E.; Sharvelle, Sybil E.; Li, Congna; Heller, Megan

    The NASA Specialized Center of Research and Training in Advanced Life Support (the ALS NSCORT), a partnership of Alabama A & M, Howard, and Purdue Universities, was established by NASA in 2002 to develop technologies that will reduce the Equivalent System Mass (ESM) of regenerative processes within future space life-support systems. A key focus area of NSCORT research has been the development of efficient microbial bioreactors for treatment of human, crop, and food-process wastes while enabling resource recovery. The approach emphasizes optimizing the energy-saving advantages of hydrolytic enzymes for biomass degradation, with focus on treatment of solid wastes including crop residue, paper, food, and human metabolic wastes, treatment of greywater, cabin air, off-gases from other treatment systems, and habitat condensate. This summary includes important findings from those projects, status of technology development, and recommendations for next steps. The Plant-based Anaerobic-Aerobic Bioreactor-Linked Operation (PAABLO) system was developed to reduce crop residue while generating energy and/or food. Plant residues initially were added directly to the bioreactor, and recalcitrant residue was used as a substrate for growing plants or mushrooms. Subsequently, crop residue was first pretreated with fungi to hydrolyze polymers recalcitrant to bacteria, and leachate from the fungal beds was directed to the anaerobic digester. Exoenzymes from the fungi pre-soften fibrous plant materials, improving recovery of materials that are more easily biodegraded to methane that can be used for energy reclamation. An Autothermal Thermophilic Aerobic Digestion (ATAD) system was developed for biodegradable solid wastes. Objectives were to increase water and nutrient recovery, reduce waste volume, and inactivate pathogens. Operational parameters of the reactor were optimized for degradation and resource recovery while minimizing system requirements and footprint. The start-up behavior

  8. Vortex breakdown in a truncated conical bioreactor

    Science.gov (United States)

    Balci, Adnan; Brøns, Morten; Herrada, Miguel A.; Shtern, Vladimir N.

    2015-12-01

    This numerical study explains the eddy formation and disappearance in a slow steady axisymmetric air-water flow in a vertical truncated conical container, driven by the rotating top disk. Numerous topological metamorphoses occur as the water height, Hw, and the bottom-sidewall angle, α, vary. It is found that the sidewall convergence (divergence) from the top to the bottom stimulates (suppresses) the development of vortex breakdown (VB) in both water and air. At α = 60°, the flow topology changes eighteen times as Hw varies. The changes are due to (a) competing effects of AMF (the air meridional flow) and swirl, which drive meridional motions of opposite directions in water, and (b) feedback of water flow on AMF. For small Hw, the AMF effect dominates. As Hw increases, the swirl effect dominates and causes VB. The water flow feedback produces and modifies air eddies. The results are of fundamental interest and can be relevant for aerial bioreactors.

  9. Robust Control Methods for a Recycle Bioreactor

    Directory of Open Access Journals (Sweden)

    Cosmin IONETE

    2001-12-01

    Full Text Available The paper presents a robust control design strategy for bioprocesses, which are characterized by strongly nonlinear dynamics. More precisely, we present the H2 methodology in order to compute the controller for a recycle Continuous Stirred Tank Bioreactor (CSTB. We consider a general method of formulating control problem, which makes use of linear fractional transformation as introduced by Doyle (1978. The formulation makes use of the general two-port configuration of the generalized plant with a generalized controller. The H2 norm is the quadratic criterion used in optimal control as LQG. The overall control objective is to minimize the H2 norm of the transfer matrix function from the weighted exogenous inputs to the weighted controlled outputs. The advantage of H2 control technique, which uses the linearized model of the CSTB, is that it is completely automated and very flexible. Finally, we prove that the closed loop control structure has very good inner robustness.

  10. Modeling bioaugmentation with nitrifiers in membrane bioreactors.

    Science.gov (United States)

    Mannucci, Alberto; Munz, Giulio; Mori, Gualtiero; Makinia, Jacek; Lubello, Claudio; Oleszkiewicz, Jan A

    2015-01-01

    Bioaugmentation with nitrifiers was studied using two pilot-scale membrane bioreactors, with the purpose of assessing the suitability of state-of-the-art activated sludge models (ASMs) in predicting the efficiency of bioaugmentation as a function of operating conditions. It was demonstrated that the temperature difference between seeding and seeded reactors (ΔT) affects bioaugmentation efficiency. Experimental data were accurately predicted when ΔT was within a range of up to 10 °C at the higher range, and when the temperature was significantly lower in the seeded reactor compared to the seeding one, standard ASMs overestimated the efficiency of bioaugmentation. A modified ASM, capable of accurately representing the behavior of seeded nitrifying biomass in the presence of high ΔT, would require the inclusion of the effect of temperature time gradients on nitrifiers. A simple linear correlation between ΔT and the Arrhenius coefficient was proposed as a preliminary step.

  11. Start-up Strategy for Continuous Bioreactors

    Directory of Open Access Journals (Sweden)

    A.C. da Costa

    1997-06-01

    Full Text Available Abstract - The start-up of continuous bioreactors is solved as an optimal control problem. The choice of the dilution rate as the control variable reduces the dimension of the system by making the use of the global balance equation unnecessary for the solution of the optimization problem. Therefore, for systems described by four or less mass balance equations, it is always possible to obtain an analytical expression for the singular arc as a function of only the state variables. The steady state conditions are shown to satisfy the singular arc expression and, based on this knowledge, a feeding strategy is proposed which leads the reactor from an initial state to the steady state of maximum productivity

  12. Dental Encounter System (DES)

    Data.gov (United States)

    Department of Veterans Affairs — Dental Encounter System (DES) is an automated health care application designed to capture critical data about the operations of VA Dental Services. Information on...

  13. Architecture des contemplatifs

    OpenAIRE

    2005-01-01

    Architecture des contemplatifs. — Il serait nécessaire de comprendre un jour, et probablement ce jour est-il proche, ce qui manque avant tout à nos grandes villes : des lieux de silence, spacieux et forts étendus, destinés à la méditation, pourvus de hautes et de longues galeries pour les intempéries ou le trop ardent soleil, où ne pénètre nulle rumeur de voitures ni de crieurs, et où une bienséance plus subtile interdirait même au prêtre l’oraison à voix haute : des édifices et des jardins q...

  14. La descente des certitudes

    Directory of Open Access Journals (Sweden)

    Frédéric Lesemann

    2010-12-01

    Full Text Available Je rédige ce texte de discussion de la thèse de l’ouvrage de Robert Castel, La Montée des incertitudes, à Montréal, en août 2010. Ces précisions initiales ont pour but de situer d’où je parle : un pays nord-américain francophone où les travaux et la personne de Robert Castel sont connus et très appréciés dans le domaine des sciences sociales, et à un moment où la crise économique découlant des crises financières internationales des deux dernières années amène les gouvernements québécois et ca...

  15. La revolution des savants

    CERN Document Server

    Chavanne, A

    1989-01-01

    Premiere cassette : - 1666 : impact de la creation de l'Academie des Sciences par Colbert, trente ans apres le proces de Galile, et au moment des disparitions de Pascal, Descartes et Fermat. Elle dirigee par le hollandais Huyggens jusqu'a sa fuite de France au moment de la revocation de l'Edit de Nantes. - 1750 : l'Encyclopedie (ou "Dictionnaire raisonne des Sciences, des Arts et des Metiers") de Diderot et d'Alembert, soutenus par Malherbes, Buffon, Condorcet et Rousseau. - 1789 : Revolution francaise. - 8 aout 1793 : l'Assemblee, par une declaration de Marat, dissout l'Academie des Sciences. Celle-ci continue cependant ses travaux pour les poids et mesures jusqu'en 1795. - la Terreur : la condamnation a mort, pas au nom d'une "Revolution qui n'a pas besoin de savants" mais pour d'autres raisons, de trois grands hommes de science : Lavoisier, Bailly et Condorcet. - 1793-1794 : Au printemps 93, le Comite de Salut Publique s'inquiete du demi-million de soldats etrangers de toutes les pays frontaliers qui essai...

  16. Rachid Santaki, Des chiffres et des litres

    OpenAIRE

    Harzoune, Mustapha

    2013-01-01

    Avec Des chiffres et des litres, Rachid Santaki signe un roman qui s’inscrit dans la pure tradition du néo-polar. Nous sommes en 1998, la Coupe du monde de football mobilise l’attention du pays. Hachim, un jeune de Saint-Denis intelligent et sensible, doué pour les études souhaite faire carrière dans le journalisme mais s’embarque dans une galère qui n’est pas faite pour lui : le deal de shit. Il faut savoir pourtant rester à sa place, ne pas jouer les gros durs quand on a une “gueule de prem...

  17. À propos des occasionnalismes

    Directory of Open Access Journals (Sweden)

    Dal Georgette

    2016-01-01

    Full Text Available Les occasionnalismes (nonce formations ou contextual formations dans la terminologie anglo-saxonne, qu’on définira provisoirement comme de “new complex word[s] created by a speaker/writer on the spur of the moment to cover some immediate need” (Bauer, 1983 : 45 ont, à notre connaissance, peu retenu l’attention des morphologues du domaine francophone. Pourtant, toutes les conditions sont désormais réunies pour que cet objet, invisible lorsqu’il s’agissait de décrire le système morphologique du français (ou d’autres langues à partir de ressources dictionnairiques, émerge en tant qu’observable dans une morphologie puisant ses données dans le réel langagier des locuteurs. Par définition en effet, on s’attend à ce qu’un occasionalisme soit absent des dictionnaires (nous verrons que, dans les faits, la situation est plus complexe que cela, et que ces contextual formations ne puissent pas être étudiées en dehors du contexte dans lequel elles ont été produites. À cet égard, la Toile et les produits qui en dérivent constituent des ressources de choix. C’est particulièrement vrai des forums, dans lesquels les internautes s’expriment librement, laissant libre cours à leur potentiel créatif (ou ce qu’ils pensent tel. Dans la présente communication, après avoir défini la notion d’occasionalisme, nous utiliserons un corpus constitué au fil d’autres recherches pour dégager des motifs récurrents propices à leur apparition, autrement dit pour établir une grammaire des occasionnalismes.

  18. Anaerobic membrane bio-reactors for severe industrial effluents and urban spill waters: The AMBROSIUS project

    NARCIS (Netherlands)

    Van Lier, J.B.; Ozgun, H.; Ersahin, M.E.; Dereli, R.K.

    2013-01-01

    With growing application experiences from aerobic membrane bioreactors, combination of membrane and anaerobic processes become more and more attractive and feasible. In anaerobic membrane bioreactors (AnMBRs), biomass and particulate organic matter are physically retained inside the reactor, providi

  19. Modular bioreactor for the remediation of liquid streams and methods for using the same

    Science.gov (United States)

    Noah, Karl S.; Sayer, Raymond L.; Thompson, David N.

    1998-01-01

    The present invention is directed to a bioreactor system for the remediation of contaminated liquid streams. The bioreactor system is composed of at least one and often a series of sub-units referred to as bioreactor modules. The modular nature of the system allows bioreactor systems be subdivided into smaller units and transported to waste sites where they are combined to form bioreactor systems of any size. The bioreactor modules further comprises reactor fill materials in the bioreactor module that remove the contaminants from the contaminated stream. To ensure that the stream thoroughly contacts the reactor fill materials, each bioreactor module comprises means for directing the flow of the stream in a vertical direction and means for directing the flow of the stream in a horizontal direction. In a preferred embodiment, the reactor fill comprises a sulfate reducing bacteria which is particularly useful for precipitating metals from acid mine streams.

  20. Le statut vitaminique des individus et des populations…

    Directory of Open Access Journals (Sweden)

    Icart Jean-Claude

    2000-05-01

    Full Text Available Comme le souligne un récent rapport du Haut comité de santé publique, le statut vitaminique des individus et des populations demeure une question d’actualité. Si les études ne révèlent plus de signes évocateurs de carence, au plus des problèmes de déficiences pour certains groupes à risque, des interrogations, demeurent malgré le contexte d’abondance, concernant la couverture des besoins, laquelle pourrait s’avérer inférieure aux valeurs considérées comme satisfaisantes.

  1. Studies on the turnover and properties of dump groundwaters in brown coal mining areas and possibilities of influencing them. Final report; Untersuchungen zum Stoffumsatz und zur Beschaffenheit der Kippengrundwaesser in Braunkohlebergbaugebieten und Moeglichkeiten zu deren Beeinflussung. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Katzur, J.; Liebner, F.; Liebner, C.; Welzel, H.P.; Hettrich, K.

    2001-07-01

    Only 6 days after the increase in pH with water saturation the concentration of iron in the pore water of the T1 sediment had dropped to a low value, 70% of which was accounted for by Fe(II). This is probably due to the almost complete precipitation of Fe(III) caused by the high pH values. Compared with the untreated variant the lowering of pH in the further course of the experiment led to a slight Fe(III) mobilisation and hence, through interaction with other reduction processes, to erratic changes in the share of Fe(II) in total Fe. Although this sediment showed a relatively low iron concentration a comparison showed that higher pH values and incubation temperatures have an influence on microbial iron reduction. [German] Im Porenwasser des Sedimentes T1 lag Eisen bereits 6 Tage nach pH-Erhoehung und Wassersaettigung nur noch in geringer Konzentration und zu ueber 70% als Fe(II) vor. Dies ist vermutlich in erster Linie auf die nahezu vollstaendige Ausfaellung von Fe(III) infolge der hohen pH-Werte zurueckzufuehren. Im weiteren Versuchsverlauf fuehrte das Absinken der pH-Werte zu einer im Vergleich zur unbehandelten Variante geringfuegigen Fe(III)-Mobilisierung und damit in Wechselwirkung mit ablaufenden Reduktionsprozessen zu unstetigen Veraenderungen in den Anteilen Fe(II) an Fe{sub ges}. Obwohl in diesem Sediment nur vergleichsweise niedrige Eisenkonzentrationen vorliegen, ergab ein Vergleich, dass hoehere pH-Werte und Inkubationtemperaturen die mikrobielle Eisenreduktion beeinflussen. (orig.)

  2. Les archives des bagnes

    Directory of Open Access Journals (Sweden)

    Archives Nationales d’Outre-Mer

    2008-01-01

    Full Text Available Les établissements pénitentiaires coloniaux étaient administrés par le ministère de la Marine et des Colonies, puis par le ministère des Colonies (1881, en liaison avec les ministères de la Justice et de l’Intérieur. Les archives ont par conséquent été versées aux Archives nationales d’outre-mer avec le fonds du ministère des Colonies.Le fonds représente environ 760 ml (5358 articles. Il concerne presque exclusivement les bagnes de Guyane et de Nouvelle-Calédonie et couvre la période 1852-1...

  3. La foi des charbonniers

    OpenAIRE

    Desbois, Evelyne; Jeanneau, Yves; Mattéi, Bruno

    2014-01-01

    Entre 1945 et 1947, deux années lourdes d'effets historiques et sociaux : la corporation minière atteint son apogée et commence son déclin. Trois regards croisés, complémentaires, portés sur un même objet, cette bataille du charbon dont on ne sait plus grand-chose, même du côté des terrils du Nord. Face au trou noir laissé dans les mémoires par cet épisode productiviste - amnésie collective remarquable - cette recherche soulève des questions iconoclastes, convoque des témoins, acteurs ou spe...

  4. Table des illustrations

    OpenAIRE

    2015-01-01

    Intégrer les Tsiganes Hongrie, 1970 (photo DR) 34 Discuter entretient la fraternité. (photo M. Stewart) 35 La veille du mariage (photo M. Stewart) 36 Le « salon » (photo M. Stewart) 37 Les activités économiques des Tsiganes sont conçues comme des jeux. (photo M. Stewart) 39 Lev cheval (photo I. Nemeth) 41 Le cortège d’un mariage (photo M. Stewart) 43 Avant le mariage (photo M. Stewart) 43 C’est par le chant (photo M. Stewart) 45 Des « frères » boivent en harmonie (photo M. Stewart) 46 Les che...

  5. Les lueurs des sables

    CERN Multimedia

    Les lueurs des sables

    2013-01-01

    Two CERN ladies are getting ready for the “Trophée Roses des Sables” rally adventure: Julie and Laetitia are finalizing the last details before setting off on Monday 7th October 2013. Julie from EN-MEF group and Laetitia from DGS-SEE group, met at the CERN Rugby club. This year, they are participating in the 100 % female rally which will take place in Morocco from 10 to 20 October. They will be carrying along 100 kg of humanitarian donation for children such as some clothes, books and medical material. Do not hesitate to show your support at their farewell party to be held on Monday 7 October, from 4 to 6 pm in front of the St Genis-Pouilly Mairie (city Hall). Follow their exciting adventure on the blog leslueursdessables.trophee-roses-des-sables.org and on their association’s Facebook page Les Lueurs des Sables.

  6. La fin des certitudes ?

    OpenAIRE

    Renard, Philippe

    2008-01-01

    2006 fut l’année anniversaire des 150 ans de la naissance de l’hydrogéologie quantitative. La théorie des variables régionalisées, ou géostatistique, est beaucoup plus jeune mais a eu un impact majeur. Aujourd’hui, tout étudiant manie avec brio le krigeage que ce soit pour cartographier une contamination, un champ de transmissivité, ou le toit d’une nappe. Mais la géostatistique n’est pas seulement cela. Son intérêt majeur réside non pas dans l’interpolation des paramètres mais dans la possib...

  7. Des millets aux nations

    OpenAIRE

    Pitsos, Nicolas

    2012-01-01

    L’auteur de ce roman construit son intrigue sur l’histoire de plusieurs familles d’une part au moment de l’effondrement d’un monde, celui des millets de l’Empire ottoman fondé sur le principe de l’identification des individus en fonction de leurs croyances religieuses et, d’autre part, lors de la mise en place d’une nouvelle organisation politique, celle des États-nations obsédés par l’idée de la définition de l’individu sur la base de critères nationaux. L'exemple narratif dominant est celui...

  8. Geschichte des SIN

    CERN Document Server

    Pritzker, Andreas

    2013-01-01

    Dieses Buch erzählt die Geschichte des Schweizerischen Instituts für Nuklearforschung (SIN). Das Institut wurde 1968 gegründet und ging 1988 ins Paul Scherrer Institut (PSI) über. Die Gründung des SIN erfolgte in einer Zeit, als die Physik weitherum als Schlüsseldisziplin für die technologische und gesellschaftliche Entwicklung galt. Der Schritt war für ein kleines Land wie die Schweiz ungewöhnliche und zeugte von Mut und Weitsicht. Ungewöhnlich waren der Folge die Leistungen des SIN im weltweiten Vergleich sowie sein Einfluss auf die schweizerische, teils auf die internationale Wissenschaftspolitik.

  9. Start-up of anaerobic ammonia oxidation bioreactor with nitrifying activated sludge

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ping; LIN Feng-mei; HU Bao-lan; CHEN Jian-song

    2004-01-01

    The anaerobic ammonia oxidation(Anammox) bioreactor was successfully started up with the nitrifying activated sludge. After anaerobically operated for 105 d, the bioreactor reached a good performance with removal percentage of both ammonia and nitrite higher high efficiency and stability because it held a large amount of biomass in the bioreactor.

  10. Operation of a fluidized-bed bioreactor for denitrification

    Energy Technology Data Exchange (ETDEWEB)

    Hancher, C W; Taylor, P A; Napier, J M

    1978-01-01

    Two denitrification fluidized-bed bioreactors of the same length (i.e., 5 m) but with different inside diameters (i.e., 5 and 10 cm) have been operated on feed ranging in nitrate concentration from 200 to 2000 g/m/sup 3/; thus far, good agreement has been obtained. Two 10-cm-ID bioreactors operating in series have also been tested; the results are in accordance with predicted results based on the performance of a 5-cm-ID bioreactor. The overall denitrification rate in the dual 10-cm-ID bioreactor system was found to be 23 kg N(NO/sub 3//sup -/)/day-m/sup 3/ using feed with a nitrate concentration of 1800 g/m/sup 3/. Data obtained in operating-temperature tests indicate that the maximum denitrification rate is achieved between 22 and 30/sup 0/C. These data will form the basis of the design of our mobile pilot plant which consists of dual 20-cm-ID by 7.3-m-long bioreactors.

  11. Operation of a fluidized-bed bioreactor for denitrification

    International Nuclear Information System (INIS)

    Two denitrification fluidized-bed bioreactors of the same length (i.e., 5 m) but with different inside diameters (i.e., 5 and 10 cm) have been operated on feed ranging in nitrate concentration from 200 to 2000 g/m3; thus far, good agreement has been obtained. Two 10-cm-ID bioreactors operating in series have also been tested; the results are in accordance with predicted results based on the performance of a 5-cm-ID bioreactor. The overall denitrification rate in the dual 10-cm-ID bioreactor system was found to be 23 kg N(NO3-)/day-m3 using feed with a nitrate concentration of 1800 g/m3. Data obtained in operating-temperature tests indicate that the maximum denitrification rate is achieved between 22 and 300C. These data will form the basis of the design of our mobile pilot plant which consists of dual 20-cm-ID by 7.3-m-long bioreactors

  12. Bioreactor for acid mine drainage control

    Science.gov (United States)

    Zaluski, Marek H.; Manchester, Kenneth R.

    2001-01-01

    A bioreactor for reacting an aqueous heavy metal and sulfate containing mine drainage solution with sulfate reducing bacteria to produce heavy metal sulfides and reduce the sulfuric acid content of the solution. The reactor is an elongated, horizontal trough defining an inlet section and a reaction section. An inlet manifold adjacent the inlet section distributes aqueous mine drainage solution into the inlet section for flow through the inlet section and reaction section. A sulfate reducing bacteria and bacteria nutrient composition in the inlet section provides sulfate reducing bacteria that with the sulfuric acid and heavy metals in the solution to form solid metal sulfides. The sulfate reducing bacteria and bacteria nutrient composition is retained in the cells of a honeycomb structure formed of cellular honeycomb panels mounted in the reactor inlet section. The honeycomb panels extend upwardly in the inlet section at an acute angle with respect to the horizontal. The cells defined in each panel are thereby offset with respect to the honeycomb cells in each adjacent panel in order to define a tortuous path for the flow of the aqueous solution.

  13. Hydrodynamics of an Electrochemical Membrane Bioreactor

    Science.gov (United States)

    Wang, Ya-Zhou; Wang, Yun-Kun; He, Chuan-Shu; Yang, Hou-Yun; Sheng, Guo-Ping; Shen, Jin-You; Mu, Yang; Yu, Han-Qing

    2015-05-01

    An electrochemical membrane bioreactor (EMBR) has recently been developed for energy recovery and wastewater treatment. The hydrodynamics of the EMBR would significantly affect the mass transfers and reaction kinetics, exerting a pronounced effect on reactor performance. However, only scarce information is available to date. In this study, the hydrodynamic characteristics of the EMBR were investigated through various approaches. Tracer tests were adopted to generate residence time distribution curves at various hydraulic residence times, and three hydraulic models were developed to simulate the results of tracer studies. In addition, the detailed flow patterns of the EMBR were acquired from a computational fluid dynamics (CFD) simulation. Compared to the tank-in-series and axial dispersion ones, the Martin model could describe hydraulic performance of the EBMR better. CFD simulation results clearly indicated the existence of a preferential or circuitous flow in the EMBR. Moreover, the possible locations of dead zones in the EMBR were visualized through the CFD simulation. Based on these results, the relationship between the reactor performance and the hydrodynamics of EMBR was further elucidated relative to the current generation. The results of this study would benefit the design, operation and optimization of the EMBR for simultaneous energy recovery and wastewater treatment.

  14. Osteocytes Mechanosensing in NASA Rotating Wall Bioreactor

    Science.gov (United States)

    Spatz, Jordan; Sibonga, Jean; Wu, Honglu; Barry, Kevin; Bouxsein, Mary; Pajevic, Paola Divieti

    2010-01-01

    Osteocyte cells are the most abundant (90%) yet least understood bone cell type in the human body. Osteocytes are theorized to be the mechanosensors and transducers of mechanical load for bones, yet the biological mechanism of this action remains elusive. However, recent discoveries in osteocyte cell biology have shed light on their importance as key mechanosensing cells regulating bone remodeling and phosphate homeostasis. The aim of this project was to characterize gene expression patterns and protein levels following exposure of MLO-Y4, a very well characterized murine osteocyte-like cell line, to simulated microgravity using the NASA Rotating Wall Vessel (RWV) Bioreactor. To determine mechanistic pathways of the osteocyte's gravity sensing ability, we evaluated in vitro gene and protein expression of osteocytes exposed to simulated microgravity. Improved understanding of the fundamental mechanisms of mechano transduction at the osteocyte cellular level may lead to revolutionary treatment otions to mitigate the effects of bone loss encountered by astronauts on long duration space missions and provide tailored treatment options for maintaining bone strength of immobilized/partially paralyzed patients here on Earth.

  15. Proteins causing membrane fouling in membrane bioreactors.

    Science.gov (United States)

    Miyoshi, Taro; Nagai, Yuhei; Aizawa, Tomoyasu; Kimura, Katsuki; Watanabe, Yoshimasa

    2015-01-01

    In this study, the details of proteins causing membrane fouling in membrane bioreactors (MBRs) treating real municipal wastewater were investigated. Two separate pilot-scale MBRs were continuously operated under significantly different operating conditions; one MBR was a submerged type whereas the other was a side-stream type. The submerged and side-stream MBRs were operated for 20 and 10 days, respectively. At the end of continuous operation, the foulants were extracted from the fouled membranes. The proteins contained in the extracted foulants were enriched by using the combination of crude concentration with an ultrafiltration membrane and trichloroacetic acid precipitation, and then separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). The N-terminal amino acid sequencing analysis of the proteins which formed intensive spots on the 2D-PAGE gels allowed us to partially identify one protein (OmpA family protein originated from genus Brevundimonas or Riemerella anatipestifer) from the foulant obtained from the submerged MBR, and two proteins (OprD and OprF originated from genus Pseudomonas) from that obtained from the side-stream MBR. Despite the significant difference in operating conditions of the two MBRs, all proteins identified in this study belong to β-barrel protein. These findings strongly suggest the importance of β-barrel proteins in developing membrane fouling in MBRs.

  16. Performance of anaerobic membrane bioreactor during digestion and thickening of aerobic membrane bioreactor excess sludge.

    Science.gov (United States)

    Hafuka, Akira; Mimura, Kazuhisa; Ding, Qing; Yamamura, Hiroshi; Satoh, Hisashi; Watanabe, Yoshimasa

    2016-10-01

    In this study, we evaluated the performance of an anaerobic membrane bioreactor in terms of digestion and thickening of excess sludge from an aerobic membrane bioreactor. A digestion reactor equipped with an external polytetrafluoroethylene tubular microfiltration membrane module was operated in semi-batch mode. Solids were concentrated by repeated membrane filtration and sludge feeding, and their concentration reached 25,400mg/L after 92d. A high chemical oxygen demand (COD) removal efficiency, i.e., 98%, was achieved during operation. A hydraulic retention time of 34d and a pulse organic loading rate of 2200mg-COD/(L-reactor) gave a biogas production rate and biogas yield of 1.33L/(reactor d) and 0.08L/g-CODinput, respectively. The external membrane unit worked well without membrane cleaning for 90d. The transmembrane pressure reached 25kPa and the filtration flux decreased by 80% because of membrane fouling after operation for 90d. PMID:27394993

  17. Classification des rongeurs

    OpenAIRE

    Mignon, Jacques; Hardouin, Jacques

    2003-01-01

    Les lecteurs du Bulletin BEDIM semblent parfois avoir des difficultés avec la classification scientifique des animaux connus comme "rongeurs" dans le langage courant. Vu les querelles existant encore aujourd'hui dans la mise en place de cette classification, nous ne nous en étonnerons guère. La brève synthèse qui suit concerne les animaux faisant ou susceptibles de faire partie du mini-élevage. The note aims at providing the main characteristics of the principal families of rodents relevan...

  18. Development of a Laminar Flow Bioreactor by Computational Fluid Dynamics

    Directory of Open Access Journals (Sweden)

    Meir Israelowitz

    2012-01-01

    Full Text Available The purpose of this study is to improve the design of a bioreactor for growing bone and other three-dimensional tissues using a computational fluid dynamics (CFD software to simulate flow through a porous scaffold, and to recommend design changes based on the results. Basic requirements for CFD modeling were that the flow in the reactor should be laminar and any flow stagnation should be avoided in order to support cellular growth within the scaffold. We simulated three different designs with different permeability values of the scaffold and tissue. Model simulation addressed flow patterns in combination with pressure distribution within the bioreactor. Pressure build-up and turbulent flow within the reactor was solved by introduction of an integrated bypass system for pressure release. The use of CFD afforded direct feedback to optimize the bioreactor design.

  19. Enhancing inhibited fermentations through a dynamic electro-membrane bioreactor

    DEFF Research Database (Denmark)

    Prado Rubio, Oscar Andres; Garde, Arvid; Rype, Jens-Ulrik;

    its strong potential for increasing productivity and product yield has been verified. REED uses ion exchange membranes and electrical potential gradients to selectively separate the target ion. The main limitation of using membrane separation combined with bioreactors is membrane fouling. REED...... technology ensures long operation time by reversing periodically the polarity of the imposed electrical field to significantly reduce the influence of membrane fouling. The periodic nature of the electrically driven membrane separation process makes the membrane bioreactor operation non trivial....... This challenging operation is associated with different dynamic behaviors of the individual units plus their interaction. The purpose of this contribution is to show the results of experimental and model based efforts done in order to investigate the operation of a membrane bioreactor. From modeling point of view...

  20. Bioreactor droplets from liposome-stabilized all-aqueous emulsions

    Science.gov (United States)

    Dewey, Daniel C.; Strulson, Christopher A.; Cacace, David N.; Bevilacqua, Philip C.; Keating, Christine D.

    2014-08-01

    Artificial bioreactors are desirable for in vitro biochemical studies and as protocells. A key challenge is maintaining a favourable internal environment while allowing substrate entry and product departure. We show that semipermeable, size-controlled bioreactors with aqueous, macromolecularly crowded interiors can be assembled by liposome stabilization of an all-aqueous emulsion. Dextran-rich aqueous droplets are dispersed in a continuous polyethylene glycol (PEG)-rich aqueous phase, with coalescence inhibited by adsorbed ~130-nm diameter liposomes. Fluorescence recovery after photobleaching and dynamic light scattering data indicate that the liposomes, which are PEGylated and negatively charged, remain intact at the interface for extended time. Inter-droplet repulsion provides electrostatic stabilization of the emulsion, with droplet coalescence prevented even for submonolayer interfacial coatings. RNA and DNA can enter and exit aqueous droplets by diffusion, with final concentrations dictated by partitioning. The capacity to serve as microscale bioreactors is established by demonstrating a ribozyme cleavage reaction within the liposome-coated droplets.

  1. Miniature Bioreactor System for Long-Term Cell Culture

    Science.gov (United States)

    Gonda, Steve R.; Kleis, Stanley J.; Geffert, Sandara K.

    2010-01-01

    A prototype miniature bioreactor system is designed to serve as a laboratory benchtop cell-culturing system that minimizes the need for relatively expensive equipment and reagents and can be operated under computer control, thereby reducing the time and effort required of human investigators and reducing uncertainty in results. The system includes a bioreactor, a fluid-handling subsystem, a chamber wherein the bioreactor is maintained in a controlled atmosphere at a controlled temperature, and associated control subsystems. The system can be used to culture both anchorage-dependent and suspension cells, which can be either prokaryotic or eukaryotic. Cells can be cultured for extended periods of time in this system, and samples of cells can be extracted and analyzed at specified intervals. By integrating this system with one or more microanalytical instrument(s), one can construct a complete automated analytical system that can be tailored to perform one or more of a large variety of assays.

  2. Sensor equipment for quantification of spatial heterogeneity in large bioreactor

    DEFF Research Database (Denmark)

    Nørregaard, Anders; Formenti, Luca Riccardo; Stocks, Stuart M.;

    Suspension cultivation in large stirred tank reactors suffers from imperfect mixing and pressure gradients due to the large size of the liquid column in the bioreactors. This leads to gradients of substrate concentrations and in turn cell population heterogeneity. The processes in large scale...... cannot be directly compared to laboratory scale experiments due to these reasons, and thus, in order to understand the large scale processes, experimental data has to be collected at large scale. The cost of acquiring data at large scale is high. The bioreactors are usually run with a limited array...... of sensors and in order to apply more sensor equipment the bioreactor has to be modified which is both costly and results in production downtime. The presence of three phases (gas, liquid, and solid), and the opaque nature of the fermentation broth together with the necessity of heat sterilization further...

  3. Streamlined bioreactor-based production of human cartilage tissues.

    Science.gov (United States)

    Tonnarelli, B; Santoro, R; Adelaide Asnaghi, M; Wendt, D

    2016-05-27

    Engineered tissue grafts have been manufactured using methods based predominantly on traditional labour-intensive manual benchtop techniques. These methods impart significant regulatory and economic challenges, hindering the successful translation of engineered tissue products to the clinic. Alternatively, bioreactor-based production systems have the potential to overcome such limitations. In this work, we present an innovative manufacturing approach to engineer cartilage tissue within a single bioreactor system, starting from freshly isolated human primary chondrocytes, through the generation of cartilaginous tissue grafts. The limited number of primary chondrocytes that can be isolated from a small clinically-sized cartilage biopsy could be seeded and extensively expanded directly within a 3D scaffold in our perfusion bioreactor (5.4 ± 0.9 doublings in 2 weeks), bypassing conventional 2D expansion in flasks. Chondrocytes expanded in 3D scaffolds better maintained a chondrogenic phenotype than chondrocytes expanded on plastic flasks (collagen type II mRNA, 18-fold; Sox-9, 11-fold). After this "3D expansion" phase, bioreactor culture conditions were changed to subsequently support chondrogenic differentiation for two weeks. Engineered tissues based on 3D-expanded chondrocytes were more cartilaginous than tissues generated from chondrocytes previously expanded in flasks. We then demonstrated that this streamlined bioreactor-based process could be adapted to effectively generate up-scaled cartilage grafts in a size with clinical relevance (50 mm diameter). Streamlined and robust tissue engineering processes, as the one described here, may be key for the future manufacturing of grafts for clinical applications, as they facilitate the establishment of compact and closed bioreactor-based production systems, with minimal automation requirements, lower operating costs, and increased compliance to regulatory guidelines.

  4. Streamlined bioreactor-based production of human cartilage tissues.

    Science.gov (United States)

    Tonnarelli, B; Santoro, R; Adelaide Asnaghi, M; Wendt, D

    2016-01-01

    Engineered tissue grafts have been manufactured using methods based predominantly on traditional labour-intensive manual benchtop techniques. These methods impart significant regulatory and economic challenges, hindering the successful translation of engineered tissue products to the clinic. Alternatively, bioreactor-based production systems have the potential to overcome such limitations. In this work, we present an innovative manufacturing approach to engineer cartilage tissue within a single bioreactor system, starting from freshly isolated human primary chondrocytes, through the generation of cartilaginous tissue grafts. The limited number of primary chondrocytes that can be isolated from a small clinically-sized cartilage biopsy could be seeded and extensively expanded directly within a 3D scaffold in our perfusion bioreactor (5.4 ± 0.9 doublings in 2 weeks), bypassing conventional 2D expansion in flasks. Chondrocytes expanded in 3D scaffolds better maintained a chondrogenic phenotype than chondrocytes expanded on plastic flasks (collagen type II mRNA, 18-fold; Sox-9, 11-fold). After this "3D expansion" phase, bioreactor culture conditions were changed to subsequently support chondrogenic differentiation for two weeks. Engineered tissues based on 3D-expanded chondrocytes were more cartilaginous than tissues generated from chondrocytes previously expanded in flasks. We then demonstrated that this streamlined bioreactor-based process could be adapted to effectively generate up-scaled cartilage grafts in a size with clinical relevance (50 mm diameter). Streamlined and robust tissue engineering processes, as the one described here, may be key for the future manufacturing of grafts for clinical applications, as they facilitate the establishment of compact and closed bioreactor-based production systems, with minimal automation requirements, lower operating costs, and increased compliance to regulatory guidelines. PMID:27232665

  5. Biological reduction of nitrate wastewater using fluidized-bed bioreactors

    International Nuclear Information System (INIS)

    There are a number of nitrate-containing wastewater sources, as concentrated as 30 wt % NO3- and as large as 2000 m3/d, in the nuclear fuel cycle as well as in many commercial processes such as fertilizer production, paper manufacturing, and metal finishing. These nitrate-containing wastewater sources can be successfully biologically denitrified to meet discharge standards in the range of 10 to 20 gN(NO3-)/m3 by the use of a fluidized-bed bioreactor. The major strain of denitrification bacteria is Pseudomonas which was derived from garden soil. In the fluidized-bed bioreactor the bacteria are allowed to attach to 0.25 to 0.50-mm-diam coal particles, which are fluidized by the upward flow of influent wastewater. Maintaining the bacteria-to-coal weight ratio at approximately 1:10 results in a bioreactor bacteria loading of greater than 20,000 g/m3. A description is given of the results of two biodenitrification R and D pilot plant programs based on the use of fluidized bioreactors capable of operating at nitrate levels up to 7000 g/m3 and achieving denitrification rates as high as 80 gN(NO3-)/d per liter of empty bioreactor volume. The first of these pilot plant programs consisted of two 0.2-m-diam bioreactors, each with a height of 6.3 m and a volume of 208 liters, operating in series. The second pilot plant was used to determine the diameter dependence of the reactors by using a 0.5-m-diam reactor with a height of 6.3 m and a volume of 1200 liters. These pilot plants operated for a period of six months and two months respectively, while using both a synthetic waste and the actual waste from a gaseous diffusion plant operated by Goodyear Atomic Corporation

  6. REPRISE DES COURS - Yoga

    CERN Document Server

    Club de Yoga

    2015-01-01

    REPRISE DES COURS – Venez nombreux ! Yoga, Sophrologie, Tai Chi La liste des cours pour le semestre allant du 1er septembre 2015 au 31 janvier 2016 est disponible sur notre site web : http://club-yoga.web.cern.ch Lieu Les cours ont lieu dans la salle des clubs, à l’entresol du restaurant No 2, Bât. 504 (dans la salle no 3 pour la Sophrologie). Prix des cours Le prix pour le semestre (environ 18 leçons) est fixé à 220 CHF plus 10 CHF d’adhésion annuelle au Club. Couple : 200 CHF par personne. 2 cours par semaine : 400 CHF. Inscriptions Les inscriptions aux cours seront prises directement auprès du professeur, lors de la 1ère séance. Avant de s’inscrire pour le semestre, il est possible d’essayer une séance gratuitement. Informations : http://club-yoga.web.cern.ch ----------------------------------------- cern.ch/club-yoga/

  7. Vom Ort des Philosophierens

    Directory of Open Access Journals (Sweden)

    Damir Barbaric

    2002-12-01

    Full Text Available Im Aufsatz wird versucht, den ursprünglichen Sinn der Platonischen Bestimmung vom Staunen als Anfang der Philosophie zu ermitteln, und zwar durch eine kritischen Abhebung von ihrer Umdeutung bei Aristoteles, und dann insbesondere in der Stoa wie auch bei Spinoza und Hegel. Dabei wird auf die frühgriechische Erfahrung vom Staunen als _______ aufmerksam gemacht, wo es vor allem die Grundstimmung des Dabeiseins des Göttlichen und der menschlichen Teilnahme am Göttlichen bedeutet. Dem entspricht die bei Platon stark hervorgehobene Rolle des “Pathetischen” am Staunen, das in der nachkommenden Tradition grundsätzlich verlorengegangen ist. Für Platon entspringt das Staunen einem nie zu überwindenden Zustand der wesentlichen philosophischen “Weglosigkeit” (_____, welche schon bei Aristoteles nur noch im Sinne eines unbedingt zu verlassenden Ausgangspunkts der methodisch sicher fortfahrenden philosophischen Wissenschaft verstanden wird. Durch ein Zurückgreifen auf die Diotimas Lehre im Dialog Symposion wird dementgegen die Sokratisch-Platonische “Weglosigkeit” als der einzig angemessene “Ort” des echten Philosophierens bestimmt, welchen es, als das “Zwischen” für das Weltspiel der Unsterblichen und Sterblichen, um jeden Preis zu bewahren und offen zu halten gilt.

  8. Die lebensvision des semonides

    Directory of Open Access Journals (Sweden)

    Milivoj Sironić

    1980-12-01

    Full Text Available Der Autor analysiert die Weibersatire des Semonides und andere seiner kurzen Fragmente. Dabei kommt er zu der Schlussfolgerung, dass sich die Verse der Satire durch eine gute Technik auszeich­ nen, dass aber auch eine unnötige Weitschweifigkeit nicht zu Ubersehen ist. Trotzdem kann man jedoch dem Dichter nicht die künstlerische Überzeugungskraft absprechen, wie auch die Ten­ denz nach Detailschilderungen und die Feinheit geistreicher Charakterisierungen. Die Aussage beinhaltet manchmal eine be­ stimmte innere Ironie in der Einfachheit der Wörter.In kurzen Fragmenten wird die Fähigkeit des Semonides sichtbar, sich sehr präzise auszudrücken. Seine ironisch-epische Sprache ist sehr reich  und verdient vom linguistischen Standpunkt aus Auf­ merksamkeit wegen ihres reichhaltigen lexischen und termino­ logischen Materials, insbesondere was die Bereiche der Tier­ welt und des Essens anbelangt.Die Weltanschauung des Dichters ist in dem ersten Fragment recht deutlich erkennbar. Da sieht man, dass er düster und pessimistisch auf das Leben blickt. Das Fehlen jeglicher positiven Einstellung hat dann den Sar­ kasmus zur Folge, mit dem der Dichter die Darstellung der Weiber einkleidet, ihn aber auch auf die Menschen schlechthin ausweitet.

  9. La physique des infinis

    CERN Document Server

    Bernardeau, Francis

    2013-01-01

    Écrire l'histoire de l'Univers, tel est l'objectif commun des physiciens des particules et des astrophysiciens. Pour y parvenir, deux approches s'épaulent : la voie de l'infiniment petit, que l'on emprunte via de gigantesques accélérateurs de particules, et celle de l'infiniment grand, dont le laboratoire est l'Univers. Un Univers qui est bien loin d'avoir livré tous ses secrets. On connaît à peine 4,8 % de la matière qui le constitue, le reste étant composé de matière noire (25,8 %) et d'énergie noire (69,4 %), toutes deux de nature inconnue. Et si la récente découverte du boson de Higgs valide le Modèle standard de la physique des particules, celui-ci est toujours incomplet et doit être étendu à ou dépassé. Est-on arrivé au bout du jeu de poupées russes de la matière ? Quelles sont les particules manquantes ? Faut-il revoir les lois fondamentales ? Quels instruments faut-il mettre en œuvre pour accéder à cette « nouvelle physique » ? Comment parler de Super Big Science aux citoye...

  10. CHAINE DES ROTISSEUR @ HILTON

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The annual gala dinner of Chaine des Rotisseurs was hosted by Hilton Beijing. The “Ballet Dinner” - a great creation for both art and fine dining lovers was taken place in varies places within the hotel, including hotel lobby, 3rd floor and lobby lounge.

  11. Die Versprachlichung des Sakralen

    DEFF Research Database (Denmark)

    Larsen, Øjvind

    2011-01-01

    Habermas claims in connection with his development of the theory of communicative action that the sacred is transformed in a positive way and can take the form of free deliberation in society, the so-called Versprachlichung des Sakralen. The thesis is that the authority which could be found in re...

  12. BIOREACTOR WITH LID FOR EASY ACCESS TO INCUBATION CAVITY

    DEFF Research Database (Denmark)

    2012-01-01

    There is provided a bioreactor which is provided with a lid (13) that facilitates access to the incubation cavity. Specifically the end wall of the incubation cavity is constituted by the lid (13) so that removal of the cap renders the incubation cavity fully accessible.......There is provided a bioreactor which is provided with a lid (13) that facilitates access to the incubation cavity. Specifically the end wall of the incubation cavity is constituted by the lid (13) so that removal of the cap renders the incubation cavity fully accessible....

  13. Over-pressurized bioreactors: application to microbial cell cultures.

    Science.gov (United States)

    Lopes, Marlene; Belo, Isabel; Mota, Manuel

    2014-01-01

    In industrial biotechnology, microbial cultures are exposed to different local pressures inside bioreactors. Depending on the microbial species and strains, the increased pressure may have detrimental or beneficial effects on cellular growth and product formation. In this review, the effects of increased air pressure on various microbial cultures growing in bioreactors under moderate total pressure conditions (maximum, 15 bar) will be discussed. Recent data illustrating the diversity of increased air pressure effects at different levels in microbial cells cultivation will be presented, with particular attention to the effects of oxygen and carbon dioxide partial pressures on cellular growth and product formation, and the concomitant effect of oxygen pressure on antioxidant cellular defense mechanisms.

  14. ANAEROBIC MEMBRANE BIOREACTORS FOR DOMESTIC WASTEWATER TREATMENT. PRELIMINARY STUDY

    Directory of Open Access Journals (Sweden)

    Luisa Vera

    2014-12-01

    Full Text Available The operation of submerged anaerobic membrane bioreactors (SAnMBRs for domestic wastewaters treatment was studied in laboratory scale, with the objective to define sustainable filtration conditions of the suspensions along the process. During continuous experiments, the organic matter degradation by anaerobic way showed an average DQOT removal of 85% and 93%. Indeed, the degradation generated biogas after 12 days of operation and its relative methane composition was of 60% after 25 days of operation. Additionally, the comparison between membrane bioreactors (MBRs performance in aerobic and anaerobic conditions in filterability terms, reported that both systems behave similarly once reached the stationary state.

  15. Injectabilite des coulis de ciment dans des milieux fissures

    Science.gov (United States)

    Mnif, Thameur

    Le travail presente ici est un bilan du travaux de recherche effectues sur l'injectabilite des coulis de ciment dans lu milieux fissures. Un certain nombre de coulis a base de ciment Portland et microfin ont ete selectionnes afin de caracteriser leur capacite a penetrer des milieux fissures. Une partie des essais a ete menee en laboratoire. L'etude rheologique des differents melanges a permis de tester l'influence de l'ajout de superplastifiant et/ou de fumee de silice sur la distribution granulometrique des coulis et par consequent sur leur capacite a injecter des colonnes de sable simulant un milieu fissure donne. La classe granulometrique d'un coulis, sa stabilite et sa fluidite sont apparus comme les trois facteurs principaux pour la reussite d'une injection. Un facteur de finesse a ete defini au cours de cette etude: base sur la classe granulometrique du ciment et sa stabilite, il peut entrer dans la formulation theorique du debit d'injection avant application sur chantier. La deuxieme et derniere partie de l'etude presente les resultats de deux projets de recherche sur l'injection realises sur chantier. L'injection de dalles de beton fissurees a permis le suivi de l'evolution des pressions avec la distance au point d'injection. L'injection de murs de maconnerie a caractere historique a montre l'importance de la definition de criteres de performance des coulis a utiliser pour traiter un milieu donne et pour un objectif donne. Plusieurs melanges peuvent ainsi etre predefinis et mis a disposition sur le chantier. La complementarite des ciments traditionnels et des ciments microfins devient alors un atout important. Le choix d'utilisation de ces melanges est fonction du terrain rencontre. En conclusion, cette recherche etablit une methodologie pour la selection des coulis a base de ciment et des pressions d'injection en fonction de l'ouverture des fissures ou joints de construction.

  16. Hydrofocusing Bioreactor Produces Anti-Cancer Alkaloids

    Science.gov (United States)

    Gonda, Steve R.; Valluri, Jagan V.

    2011-01-01

    A methodology for growing three-dimensional plant tissue models in a hydrodynamic focusing bioreactor (HFB) has been developed. The methodology is expected to be widely applicable, both on Earth and in outer space, as a means of growing plant cells and aggregates thereof under controlled conditions for diverse purposes, including research on effects of gravitation and other environmental factors upon plant growth and utilization of plant tissue cultures to produce drugs in quantities greater and at costs lower than those of conventional methodologies. The HFB was described in Hydro focus - ing Bioreactor for Three-Dimensional Cell Culture (MSC-22358), NASA Tech Briefs, Vol. 27, No. 3 (March 2003), page 66. To recapitulate: The HFB offers a unique hydrofocusing capability that enables the creation of a low-shear liquid culture environment simultaneously with the herding of suspended cells and tissue assemblies and removal of unwanted air bubbles. The HFB includes a rotating cell-culture vessel with a centrally located sampling port and an internal rotating viscous spinner attached to a rotating base. The vessel and viscous spinner can be made to rotate at the same speed and direction or different speeds and directions to tailor the flow field and the associated hydrodynamic forces in the vessel in order to obtain low-shear suspension of cells and control of the locations of cells and air bubbles. For research and pharmaceutical-production applications, the HFB offers two major benefits: low shear stress, which promotes the assembly of cells into tissue-like three-dimensional constructs; and randomization of gravitational vectors relative to cells, which affects production of medicinal compounds. Presumably, apposition of plant cells in the absence of shear forces promotes cell-cell contacts, cell aggregation, and cell differentiation. Only gentle mixing is necessary for distributing nutrients and oxygen. It has been postulated that inasmuch as cells in the simulated

  17. A comparison of bioreactors for culture of fetal mesenchymal stem cells for bone tissue engineering.

    Science.gov (United States)

    Zhang, Zhi-Yong; Teoh, Swee Hin; Teo, Erin Yiling; Khoon Chong, Mark Seow; Shin, Chong Woon; Tien, Foo Toon; Choolani, Mahesh A; Chan, Jerry K Y

    2010-11-01

    Bioreactors provide a dynamic culture system for efficient exchange of nutrients and mechanical stimulus necessary for the generation of effective tissue engineered bone grafts (TEBG). We have shown that biaxial rotating (BXR) bioreactor-matured human fetal mesenchymal stem cell (hfMSC) mediated-TEBG can heal a rat critical sized femoral defect. However, it is not known whether optimal bioreactors exist for bone TE (BTE) applications. We systematically compared this BXR bioreactor with three most commonly used systems: Spinner Flask (SF), Perfusion and Rotating Wall Vessel (RWV) bioreactors, for their application in BTE. The BXR bioreactor achieved higher levels of cellularity and confluence (1.4-2.5x, p bioreactors operating in optimal settings. BXR bioreactor-treated scaffolds experienced earlier and more robust osteogenic differentiation on von Kossa staining, ALP induction (1.2-1.6×, p bioreactor-treated grafts, but not with the other three. BXR bioreactor enabled superior cellular proliferation, spatial distribution and osteogenic induction of hfMSC over other commonly used bioreactors. In addition, we developed and validated a non-invasive quantitative micro CT-based technique for analyzing neo-tissue formation and its spatial distribution within scaffolds.

  18. Introducing Textiles as Material of Construction of Ethanol Bioreactors

    Directory of Open Access Journals (Sweden)

    Osagie A. Osadolor

    2014-11-01

    Full Text Available The conventional materials for constructing bioreactors for ethanol production are stainless and cladded carbon steel because of the corrosive behaviour of the fermenting media. As an alternative and cheaper material of construction, a novel textile bioreactor was developed and examined. The textile, coated with several layers to withstand the pressure, resist the chemicals inside the reactor and to be gas-proof was welded to form a 30 L lab reactor. The reactor had excellent performance for fermentative production of bioethanol from sugar using baker’s yeast. Experiments with temperature and mixing as process parameters were performed. No bacterial contamination was observed. Bioethanol was produced for all conditions considered with the optimum fermentation time of 15 h and ethanol yield of 0.48 g/g sucrose. The need for mixing and temperature control can be eliminated. Using a textile bioreactor at room temperature of 22 °C without mixing required 2.5 times longer retention time to produce bioethanol than at 30 °C with mixing. This will reduce the fermentation investment cost by 26% for an ethanol plant with capacity of 100,000 m3 ethanol/y. Also, replacing one 1300 m3 stainless steel reactor with 1300 m3 of the textile bioreactor in this plant will reduce the fermentation investment cost by 19%.

  19. Modelling and characterization of an airlift-loop bioreactor.

    NARCIS (Netherlands)

    Verlaan, P.

    1987-01-01

    An airlift-loop reactor is a bioreactor for aerobic biotechnological processes. The special feature of the ALR is the recirculation of the liquid through a downcomer connecting the top and the bottom of the main bubbling section. Due to the high circulation-flow rate, efficient mixing and oxygen tra

  20. Anaerobic Membrane Bioreactors For Cost-Effective Municipal Water Reuse

    NARCIS (Netherlands)

    Özgün, H.

    2015-01-01

    In recent years, anaerobic membrane bioreactor (AnMBR) technology has been increasingly researched for municipal wastewater treatment as a means to produce nutrient-rich, solids free effluents with low levels of pathogens, while occupying a small footprint. An AnMBR can be used not only for on-site

  1. 40 CFR 258.41 - Project XL Bioreactor Landfill Projects.

    Science.gov (United States)

    2010-07-01

    ... WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Design Criteria § 258.41 Project XL Bioreactor... reference with 5 U.S.C. 552(a) and 1 CFR part 51. These methods are available from The American Society for... landfills operated by the Waste Management, Inc. or its successors: The Maplewood Recycling and...

  2. Reduced Order Dead-Beat Observers for a Bioreactor

    CERN Document Server

    Karafyllis, Iasson

    2010-01-01

    This paper studies the strong observability property and the reduced-order dead-beat observer design problem for a continuous bioreactor. New relationships between coexistence and strong observability, and checkable sufficient conditions for strong observability, are established for a chemostat with two competing microbial species. Furthermore, the dynamic output feedback stabilization problem is solved for the case of one species.

  3. Numerical study of fluid motion in bioreactor with two mixers

    Energy Technology Data Exchange (ETDEWEB)

    Zheleva, I., E-mail: izheleva@uni-ruse.bg [Department of Heat Technology, Hydraulics and Ecology, Angel Kanchev University of Rousse, 8 Studentska str., 7017 Rousse (Bulgaria); Lecheva, A., E-mail: alecheva@uni-ruse.bg [Department of Mathematics, Angel Kanchev University of Rousse, 8 Studentska str., 7017 Rousse (Bulgaria)

    2015-10-28

    Numerical study of hydrodynamic laminar behavior of a viscous fluid in bioreactor with multiple mixers is provided in the present paper. The reactor is equipped with two disk impellers. The fluid motion is studied in stream function-vorticity formulation. The calculations are made by a computer program, written in MATLAB. The fluid structure is described and numerical results are graphically presented and commented.

  4. NASA's Bioreactor: Growing Cells in a Microgravity Environment. Educational Brief.

    Science.gov (United States)

    National Aeronautics and Space Administration, Washington, DC.

    This brief discusses growing cells in a microgravity environment for grades 9-12. Students are provided with plans for building a classroom bioreactor that can then be used with the included activity on seed growth in a microgravity environment. Additional experimental ideas are also suggested along with a history and background on microgravity…

  5. Hydraulic flow characteristics of agricultural residues for denitrifying bioreactor media

    Science.gov (United States)

    Denitrifying bioreactors are a promising technology to mitigate agricultural subsurface drainage nitrate-nitrogen losses, a critical water quality goal for the Upper Mississippi River Basin. This study was conducted to evaluate the hydraulic properties of agricultural residues that are potential bio...

  6. MEASUREMENT OF FUGITIVE EMISSIONS AT A BIOREACTOR LANDFILL

    Science.gov (United States)

    This report focuses on three field campaigns performed in 2002 and 2003 to measure fugitive emissions at a bioreactor landfill in Louisville, KY, using an open-path Fourier transform infrared spectrometer. The study uses optical remote sensing-radial plume mapping. The horizontal...

  7. Simulating woodchip bioreactor performance using a dual-porosity model

    Science.gov (United States)

    Nitrate in the Nation's surface waters has been a persistent health and ecological problem. The major source of nitrate is tile drainage from agricultural row crops. Denitrification bioreactors have been shown to be effective in removing much of the nitrate from tile drains. While we understand i...

  8. Optimising Microbial Growth with a Bench-Top Bioreactor

    Science.gov (United States)

    Baker, A. M. R.; Borin, S. L.; Chooi, K. P.; Huang, S. S.; Newgas, A. J. S.; Sodagar, D.; Ziegler, C. A.; Chan, G. H. T.; Walsh, K. A. P.

    2006-01-01

    The effects of impeller size, agitation and aeration on the rate of yeast growth were investigated using bench-top bioreactors. This exercise, carried out over a six-month period, served as an effective demonstration of the importance of different operating parameters on cell growth and provided a means of determining the optimisation conditions…

  9. Performance of Submerged Membrane Bioreactor for Domestic Wastewater Treatment

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In the present research, a submerged membrane bioreactor was tested to treat domestic wastewater. Three experimental runs were conducted all with a hydraulic retention time of 5h and sludge retention times (SRTs) of 5, 10, and 20 d. The pollutant removal performance of the membrane bioreactor, the membrane effluent quality, and a kinetic model for sludge growth in the bioreactor were investigated. The combined process was capable of removing over 90% of both COD (chemical oxygen demand) and NH3-N on the average. The total removal for COD was almost independent of SRT, but that for NH3-N improved with increasing SRT. Membrane effluent quality meets the water quality standard for reuse issued by the Ministry of Construction of China. Increasing SRT causes the concentrations of suspended solids (SS) and volatile suspended solids (VSS) in the bioreactor to increase. However, the ratio of VSS/SS did not change much. Kinetic analysis showed that the sludge yield coefficient (kg-VSS·kg-COD-1) and the endogenous coefficient of microorganisms were 0.25 and 0.04d-1, which are similar to those of the conventional activated sludge process.

  10. Internal hydraulics of an agricultural drainage denitrification bioreactor

    Science.gov (United States)

    Denitrification bioreactors to reduce the amount of nitrate-nitrogen in agricultural drainage are now being deployed across the U.S. Midwest. However, there are still many unknowns regarding internal hydraulic-driven processes in these "black box" engineered treatment systems. To improve this unders...

  11. Expression Systems and Species Used for Transgenic Animal Bioreactors

    Directory of Open Access Journals (Sweden)

    Yanli Wang

    2013-01-01

    Full Text Available Transgenic animal bioreactors can produce therapeutic proteins with high value for pharmaceutical use. In this paper, we compared different systems capable of producing therapeutic proteins (bacteria, mammalian cells, transgenic plants, and transgenic animals and found that transgenic animals were potentially ideal bioreactors for the synthesis of pharmaceutical protein complexes. Compared with other transgenic animal expression systems (egg white, blood, urine, seminal plasma, and silkworm cocoon, the mammary glands of transgenic animals have enormous potential. Compared with other mammalian species (pig, goat, sheep, and cow that are currently being studied as bioreactors, rabbits offer many advantages: high fertility, easy generation of transgenic founders and offspring, insensitivity to prion diseases, relatively high milk production, and no transmission of severe diseases to humans. Noticeably, for a small- or medium-sized facility, the rabbit system is ideal to produce up to 50 kg of protein per year, considering both economical and hygienic aspects; rabbits are attractive candidates for the mammary-gland-specific expression of recombinant proteins. We also reviewed recombinant proteins that have been produced by targeted expression in the mammary glands of rabbits and discussed the limitations of transgenic animal bioreactors.

  12. Bioreactors for removing methyl bromide following contained fumigations

    Science.gov (United States)

    Miller, L.G.; Baesman, S.M.; Oremland, R.S.

    2003-01-01

    Use of methyl bromide (MeBr) as a quarantine, commodity, or structural fumigant is under scrutiny because its release to the atmosphere contributes to the depletion of stratospheric ozone. A closed-system bioreactor consisting of 0.5 L of a growing culture of a previously described bacterium, strain IMB-1, removed MeBr (> 110 ??mol L-1) from recirculating air. Strain IMB-1 grew slowly to high cell densities in the bioreactor using MeBr as its sole carbon and energy source. Bacterial oxidation of MeBr produced CO2 and hydrobromic acid (HBr), which required continuous neutralization with NaOH for the system to operate effectively. Strain IMB-1 was capable of sustained oxidation of large amounts of MeBr (170 mmol in 46 d). In an open-system bioreactor (10-L fermenter), strain IMB-1 oxidized a continuous supply of MeBr (220 ??mol L-1 in air). Growth was continuous, and 0.5 mol of MeBr was removed from the air supply in 14 d. The specific rate of MeBr oxidation was 7 ?? 10-16 mol cell-1 h-1. Bioreactors such as these can therefore be used to remove large quantities of contaminant MeBr, which opens the possibility of biodegradation as a practical means for its disposal.

  13. Oxygen Sensors Monitor Bioreactors and Ensure Health and Safety

    Science.gov (United States)

    2014-01-01

    In order to cultivate healthy bacteria in bioreactors, Kennedy Space Center awarded SBIR funding to Needham Heights, Massachusetts-based Polestar Technologies Inc. to develop sensors that could monitor oxygen levels. The result is a sensor now widely used by pharmaceutical companies and medical research universities. Other sensors have also been developed, and in 2013 alone the company increased its workforce by 50 percent.

  14. Gel layer formation on membranes in Membrane Bioreactors

    NARCIS (Netherlands)

    Van den Brink, P.F.H.

    2014-01-01

    The widespread application of membrane bioreactors (MBRs) for municipal wastewater treatment is hampered by membrane fouling. Fouling increases energy demand, reduces process performance and creates the need for more frequent (chemical) membrane cleaning or replacement. Membrane fouling in MBRs is k

  15. Microfluidic bioreactors for culture of non-adherent cells

    DEFF Research Database (Denmark)

    Shah, Pranjul Jaykumar; Vedarethinam, Indumathi; Kwasny, Dorota;

    2011-01-01

    Microfluidic bioreactors (μBR) are becoming increasingly popular for cell culture, sample preparation and analysis in case of routine genetic and clinical diagnostics. We present a novel μBR for non-adherent cells designed to mimic in vivo perfusion of cells based on diffusion of media through...

  16. Thermophillic Sidestream Anaerobic Membrane Bioreactors: The Shear Rate Dilemma

    NARCIS (Netherlands)

    Jeison, D.A.; Telkamp, P.; Lier, van J.B.

    2009-01-01

    Anaerobic biomass retention under thermophilic conditions has proven difficult. Membrane filtration can be used as alternative way to achieve high sludge concentrations. This research studied the feasibility of anaerobic membrane bioreactors (AnMBRs) under thermophilic conditions. A sidestream MBR w

  17. Expansion of Human Mesenchymal Stem Cells in a Microcarrier Bioreactor.

    Science.gov (United States)

    Tsai, Ang-Chen; Ma, Teng

    2016-01-01

    Human mesenchymal stem cells (hMSCs) are considered as a primary candidate in cell therapy owing to their self-renewability, high differentiation capabilities, and secretions of trophic factors. In clinical application, a large quantity of therapeutically competent hMSCs is required that cannot be produced in conventional petri dish culture. Bioreactors are scalable and have the capacity to meet the production demand. Microcarrier suspension culture in stirred-tank bioreactors is the most widely used method to expand anchorage dependent cells in a large scale. Stirred-tank bioreactors have the potential to scale up and microcarriers provide the high surface-volume ratio. As a result, a spinner flask bioreactor with microcarriers has been commonly used in large scale expansion of adherent cells. This chapter describes a detailed culture protocol for hMSC expansion in a 125 mL spinner flask using microcarriers, Cytodex I, and a procedure for cell seeding, expansion, metabolic sampling, and quantification and visualization using microculture tetrazolium (MTT) reagent. PMID:27032950

  18. Reconstruction of liver organoid using a bioreactor

    Institute of Scientific and Technical Information of China (English)

    Masaya Saito; Tomokazu Matsuura; Takahiro Masaki; Haruka Maehashi; Keiko Shimizu; Yoshiaki Hataba; Tohru Iwahori; Tetsuro Suzuki; Filip Braet

    2006-01-01

    AIM: To develop the effective technology for reconstruction of a liver organ in vitro using a bio-artificial liver.METHODS: We previously reported that a radial-flow bioreactor (RFB) could provide a three-dimensional highdensity culture system. We presently reconstructed the liver organoid using a functional human hepatocellular carcinoma cell line (FLC-5) as hepatocytes together with mouse immortalized sinusoidal endothelial cell (SEC) line M1 and mouse immortalized hepatic stellate cell (HSC) line A7 as non parenchymal cells in the RFB. Two x 107 FLC-5 cells were incubated in the RFB. After 5 d, 2 x 107 A7 cells were added in a similar manner followed by another addition of 107 M1 cells 5 d later. After three days of perfusion, some cellulose beads with the adherent cells were harvested. The last incubation period included perfusion with 200 nmol/L swinholide A for 2 h and then the remaining cellulose beads along with adherent cells were harvested from the RFB. The cell morphology was observed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). To assess hepatocyte function, we compared mRNA expression for urea cycle enzymes as well as albumin synthesis by FLC-5 in monolayer cultures compared to those of single-type cultures and cocultures in the RFB.RESULTS: By transmission electron microscopy, FLC-5,M1, and A7 were arranged in relation to the perfusion side in a liver-like organization. Structures resembling bile canaliculi were seen between FCL-5 cells. Scanning electron microscopy demonstrated fenestrae on SEC surfaces. The number of vesiculo-vacuolar organelles (WO) and fenestrae increased when we introduced the actin-binding agent swinholide-A in the RFB for 2h. With respect to liver function, urea was found in the medium,and expression of mRNAs encoding arginosuccinate synthetase and arginase increased when the three cell types were cocultured in the RFB. However, albumin synthesis decreased.CONCLUSION: Co-culture in the RFB

  19. Biological hydrogen production using a membrane bioreactor.

    Science.gov (United States)

    Oh, Sang-Eun; Iyer, Prabha; Bruns, Mary Ann; Logan, Bruce E

    2004-07-01

    A cross-flow membrane was coupled to a chemostat to create an anaerobic membrane bioreactor (MBR) for biological hydrogen production. The reactor was fed glucose (10,000 mg/L) and inoculated with a soil inoculum heat-treated to kill non-spore-forming methanogens. Hydrogen gas was consistently produced at a concentration of 57-60% in the headspace under all conditions. When operated in chemostat mode (no flow through the membrane) at a hydraulic retention time (HRT) of 3.3 h, 90% of the glucose was removed, producing 2200 mg/L of cells and 500 mL/h of biogas. When operated in MBR mode, the solids retention time (SRT) was increased to SRT = 12 h producing a solids concentration in the reactor of 5800 mg/L. This SRT increased the overall glucose utilization (98%), the biogas production rate (640 mL/h), and the conversion efficiency of glucose-to-hydrogen from 22% (no MBR) to 25% (based on a maximum of 4 mol-H(2)/mol-glucose). When the SRT was increased from 5 h to 48 h, glucose utilization (99%) and biomass concentrations (8,800 +/- 600 mg/L) both increased. However, the biogas production decreased (310 +/- 40 mL/h) and the glucose-to-hydrogen conversion efficiency decreased from 37 +/- 4% to 18 +/- 3%. Sustained permeate flows through the membrane were in the range of 57 to 60 L/m(2) h for three different membrane pore sizes (0.3, 0.5, and 0.8 microm). Most (93.7% to 99.3%) of the membrane resistance was due to internal fouling and the reversible cake resistance, and not the membrane itself. Regular backpulsing was essential for maintaining permeate flux through the membrane. Analysis of DNA sequences using ribosomal intergenic spacer analysis indicated bacteria were most closely related to members of Clostridiaceae and Flexibacteraceae, including Clostridium acidisoli CAC237756 (97%), Linmingia china AF481148 (97%), and Cytophaga sp. MDA2507 AF238333 (99%). No PCR amplification of 16s rRNA genes was obtained when archaea-specific primers were used.

  20. Chimie des processus biologiques

    OpenAIRE

    Fontecave, Marc

    2016-01-01

    Cours : Chimie biologique radicalaire : de l’origine de l’ADN au métabolisme d’aujourd’hui Il est généralement admis que les radicaux libres, espèces chimiques très réactives, sont des poisons pour les systèmes vivants qui ont élaboré des mécanismes efficaces pour s’en protéger et s’en débarrasser lorsqu’ils viennent à se former, par accident. Par exemple ce qu’on appelle communément le stress oxydant est une situation caractérisée par une accumulation de radicaux issus de l’oxygène moléculai...

  1. Zur Biographie des Thomas Finck

    OpenAIRE

    Graf, Klaus

    2009-01-01

    Aus der Überlieferung der Werke des Mönchs Thomas Finck ergeben sich die Jahre 1489 und 1507 als Eckdaten seiner derzeit bekannten Lebenszeugnisse. Nach Ausweis des Cgm 6940 beendete Thomas Finck, der sich als Bruder des Benediktinerordens bezeichnet, am 8. Juli 1489 im Benediktinerkloster Elchingen die Übertragung der pseudothomasischen Schrift 'De beatitudine'. Der nur in der Karlsruher Handschrift St. Georgen 84 (möglicherweise ein Konzeptautograph) überlieferten Vorrede und Datierung sein...

  2. Plus que des engrais

    OpenAIRE

    Fuchs, Jacques G.

    2008-01-01

    COMPOSTS ET RÉSIDUS DE MÉTHANISATION Compte tenu de l'augmentation du prix des engrais minéraux, il se manifeste un intérêt croissant pour les composts et les résidus de méthanisation. En plus de leur effet nutritif, ces produits de substitution stimulent l'activité biologique dans le sol et peuvent exercer une action favorable sur le pH.

  3. A la recherche des hybrides

    OpenAIRE

    DUPONT, Ariane

    2013-01-01

    Mon programme de recherche se développe autour de deux axes : 1/ l’analyse de la demande de transport des voyageurs et de ses impacts environnementaux pour permettre la définition et l’évaluation des politiques de transport durable, et 2/ une analyse des méthodes et des outils économétriques, notamment ceux définis et développés par Ragnar Frisch. Ces deux champs semblent si disjoints que l’on pourrait croire à une schizophrénie développée suite à un basculement de parcou...

  4. Dictionnaire des risques psychosociaux

    CERN Document Server

    Zawieja, Philippe

    2014-01-01

    Stress, suicide, harcèlement, épuisement professionnel, workaholism... Au-delà de la souffrance qu'elles désignent, ces notions souvent récentes constituent une approche inédite, et demandent à mieux être comprises, dans leur ensemble et isolément. C'est tout l'enjeu de ce dictionnaire, pionnier en son genre. Le lecteur y trouvera représentés, avec les 314 entrées (rédigées par 251 contributeurs) qui le composent, tous les champs disciplinaires s'intéressant à la souffrance au travail : psychologie du travail et des organisations, psychologie sociale et psychosociologie, psychanalyse, psychopathologie et psychiatrie, ergonomie, sociologie du travail et des organisations, médecine du travail, droit du travail et de la sécurité sociale, sciences de gestion, philosophie... Y sont détaillés les principaux concepts, notions, approches, méthodes, théories, outils, études, etc., ayant cours dans l'étude des risques psychosociaux, mais aussi certaines professions emblématiques (infirmières,...

  5. BIOREACTOR ECONOMICS, SIZE AND TIME OF OPERATION (BEST) COMPUTER SIMULATOR FOR DESIGNING SULFATE-REDUCING BACTERIA FIELD BIOREACTORS

    Science.gov (United States)

    BEST (bioreactor economics, size and time of operation) is an Excel™ spreadsheet-based model that is used in conjunction with the public domain geochemical modeling software, PHREEQCI. The BEST model is used in the design process of sulfate-reducing bacteria (SRB) field bioreacto...

  6. Hepatocyte function within a stacked double sandwich culture plate cylindrical bioreactor for bioartificial liver system.

    Science.gov (United States)

    Xia, Lei; Arooz, Talha; Zhang, Shufang; Tuo, Xiaoye; Xiao, Guangfa; Susanto, Thomas Adi Kurnia; Sundararajan, Janani; Cheng, Tianming; Kang, Yuzhan; Poh, Hee Joo; Leo, Hwa Liang; Yu, Hanry

    2012-11-01

    Bioartificial liver (BAL) system is promising as an alternative treatment for liver failure. We have developed a bioreactor with stacked sandwich culture plates for the application of BAL. This bioreactor design addresses some of the persistent problems in flat-bed bioreactors through increasing cell packing capacity, eliminating dead flow, regulating shear stress, and facilitating the scalability of the bioreactor unit. The bioreactor contained a stack of twelve double-sandwich-culture plates, allowing 100 million hepatocytes to be housed in a single cylindrical bioreactor unit (7 cm of height and 5.5 cm of inner diameter). The serial flow perfusion through the bioreactor increased cell-fluid contact area for effective mass exchange. With the optimal perfusion flow rate, shear stress was minimized to achieve high and uniform cell viabilities across different plates in the bioreactor. Our results demonstrated that hepatocytes cultured in the bioreactor could re-establish cell polarity and maintain liver-specific functions (e.g. albumin and urea synthesis, phase I&II metabolism functions) for seven days. The single bioreactor unit can be readily scaled up to house adequate number of functional hepatocytes for BAL development.

  7. Die Klassifizierung des Blutdrucks

    Directory of Open Access Journals (Sweden)

    Skrabal F

    2004-01-01

    Full Text Available Während der systolische Blutdruck in der Bevölkerung mit zunehmendem Lebensalter in jedem Dezennium weiter ansteigt, beginnt der diastolische Blutdruck ab dem 50. Lebensjahr für jede systolische Blutdruckstratifizierung als Ausdruck einer zunehmenden Gefäßschädigung wieder zu sinken. Deswegen muß der Blutdruck ausschließlich nach dem systolischen Blutdruck klassifiziert werden. Die Häufigkeitsverteilung des systolischen und diastolischen Blutdrucks innerhalb der Bevölkerung entspricht einer Gauss'schen Glockenkurve. Jede Unterteilung in normotensiv und hypertensiv entspricht deshalb einer völlig willkürlichen Dichotomisierung. Je niedriger der Blutdruck, desto geringer die mechanische Belastung der Blutgefäße und desto geringer auch die mechanisch induzierten Gefäßschäden. Das war der Grund für die zuletzt vom "7th JNC on Prevention, Detection and Treatment of Hypertension" des NIH, USA, vorgenommene Klassifizierung des Blutdrucks in normal (kleiner als 120 mmHg systolisch, prähypertensiv (120-140 mmHg und Hypertonie-Stadium I (140-160 mmHg systolisch und Hypertonie-Stadium II ( 160 mmHg systolisch. Damit muß leider die nahezu gesamte gesunde österreichische Bevölkerung, die nach bisheriger Klassifikation noch keinen Hochdruck aufweist, als prähypertensiv klassifiziert werden. Ein wirklicher Informationsgewinn (der ja mit der Klassifikation bezweckt wird ist meiner Meinung nach damit nicht mehr gegeben. Die Österreichische Hochdruckliga schlägt eine zusätzliche Klassifikation des Blutdrucks nach dem „Pressure Load“ vor, welches aus einer statistisch aussagekräftigen Zahl von Selbstmessungen leicht zu errechnen ist. Jedes Pressure Load von mehr als 20 % (mehr als 20 % der selbst gemessenen Blutdruckwerte 135/85 mmHg entspricht einer Hypertonie, die je nach Höhe der Blutdruckwerte entweder mit Änderungen des Lebensstils oder mit antihypertensiver Medikation zu bekämpfen ist.

  8. Reticulation des fibres lignocellulosiques

    Science.gov (United States)

    Landrevy, Christel

    Pour faire face à la crise économique la conception de papier à valeur ajoutée est développée par les industries papetières. Le but de se projet est l'amélioration des techniques actuelles de réticulation des fibres lignocellulosiques de la pâte à papier visant à produire un papier plus résistant. En effet, lors des réactions de réticulation traditionnelles, de nombreuses liaisons intra-fibres se forment ce qui affecte négativement l'amélioration anticipée des propriétés physiques du papier ou du matériau produit. Pour éviter la formation de ces liaisons intra-fibres, un greffage sur les fibres de groupements ne pouvant pas réagir entre eux est nécessaire. La réticulation des fibres par une réaction de « click chemistry » appelée cycloaddition de Huisgen entre un azide et un alcyne vrai, catalysée par du cuivre (CuAAC) a été l'une des solutions trouvée pour remédier à ce problème. De plus, une adaptation de cette réaction en milieux aqueux pourrait favoriser son utilisation en milieu industriel. L'étude que nous désirons entreprendre lors de ce projet vise à optimiser la réaction de CuAAC et les réactions intermédiaires (propargylation, tosylation et azidation) sur la pâte kraft, en milieu aqueux. Pour cela, les réactions ont été adaptées en milieu aqueux sur la cellulose microcristalline afin de vérifier sa faisabilité, puis transférée à la pâte kraft et l'influence de différents paramètres comme le temps de réaction ou la quantité de réactifs utilisée a été étudiée. Dans un second temps, une étude des différentes propriétés conférées au papier par les réactions a été réalisée à partir d'une série de tests papetiers optiques et physiques. Mots Clés Click chemistry, Huisgen, CuAAC, propargylation, tosylation, azidation, cellulose, pâte kraft, milieu aqueux, papier.

  9. Pyramide des âges et gestion des ressources humaines

    OpenAIRE

    Godelier, Eric

    2007-01-01

    L'utilisation de la pyramide des âges dans les discours des directeurs de ressources humaines s'est développée au cours des années 1980. Elle renvoie au choix d'un critère de sélection de salariés jugés en sureffectif. Derrière l'âge et ses représentations, c'est bien la question de la capacité des salariés à s'adapter au changement de l'entreprise qui est posée. En définitive, il s'agit de savoir s'il existe des conditions démographiques au changement organisationnel.

  10. Development of a bioreactor based on magnetically stabilized fluidized bed for bioartificial liver.

    Science.gov (United States)

    Deng, Fei; Chen, Li; Zhang, Ying; Zhao, Shan; Wang, Yu; Li, Na; Li, Shen; Guo, Xin; Ma, Xiaojun

    2015-12-01

    Bioartificial liver (BAL) based on microcapsules has been proposed as a potential treatment for acute liver failure. The bioreactors used in such BAL are usually expected to achieve sufficient flow rate and minimized void volume for effective application. Due to the superiorities in bed pressure drop and operation velocity, magnetically stabilized fluidized beds (MSFBs) show the potential to serve as ideal microcapsule-based bioreactors. In the present study, we attempted to develop a microcapsule-based MSFB bioreactor for bioartificial liver device. Compared to conventional-fluidized bed bioreactors, the bioreactor presented here increased perfusion velocity and decreased void volume significantly. Meanwhile, the mechanical stability as well as the immunoisolation property of magnetite microcapsules were well maintained during the fluidization. Besides, the magnetite microcapsules were found no toxicity to cell survival. Therefore, our study might provide a novel approach for the design of microcapsule-based bioartificial liver bioreactors.

  11. Production of bacterial cellulose membranes in a modified airlift bioreactor by Gluconacetobacter xylinus.

    Science.gov (United States)

    Wu, Sheng-Chi; Li, Meng-Hsun

    2015-10-01

    In this study, a novel bioreactor for producing bacterial cellulose (BC) is proposed. Traditional BC production uses static culture conditions and produces a gelatinous membrane. The potential for using various types of bioreactor, including a stirred tank, conventional airlift, and modified airlift with a rectangular wire-mesh draft tube, in large-scale production has been investigated. The BC obtained from these bioreactors is fibrous or in pellet form. Our proposed airlift bioreactor produces a membrane-type BC from Gluconacetobacter xylinus, the water-holding capacity of which is greater than that of cellulose types produced using static cultivation methods. The Young's modulus of the product can be manipulated by varying the number of net plates in the modified airlift bioreactor. The BC membrane produced using the proposed bioreactor exhibits potential for practical application.

  12. Production of bacterial cellulose membranes in a modified airlift bioreactor by Gluconacetobacter xylinus.

    Science.gov (United States)

    Wu, Sheng-Chi; Li, Meng-Hsun

    2015-10-01

    In this study, a novel bioreactor for producing bacterial cellulose (BC) is proposed. Traditional BC production uses static culture conditions and produces a gelatinous membrane. The potential for using various types of bioreactor, including a stirred tank, conventional airlift, and modified airlift with a rectangular wire-mesh draft tube, in large-scale production has been investigated. The BC obtained from these bioreactors is fibrous or in pellet form. Our proposed airlift bioreactor produces a membrane-type BC from Gluconacetobacter xylinus, the water-holding capacity of which is greater than that of cellulose types produced using static cultivation methods. The Young's modulus of the product can be manipulated by varying the number of net plates in the modified airlift bioreactor. The BC membrane produced using the proposed bioreactor exhibits potential for practical application. PMID:25823854

  13. Digitalisierung des Kulturellen Erbes (Europas)

    NARCIS (Netherlands)

    Gruber, Marion

    2011-01-01

    Gruber, M. R. (2011, 13 December). Digitalisierung des Kulturellen Erbes (Europas). Guest lecture at the IPMZ - Institute of Mass Communication and Media Research, Devision Media Change & Innovation, University of Zurich, Switzerland. (http://www.slideshare.net/em3rg3/digitalisierung-des-kulturelle

  14. Digitalisierung des Kulturellen Erbes (Europas)

    OpenAIRE

    Gruber, Marion

    2011-01-01

    Gruber, M. R. (2011, 13 December). Digitalisierung des Kulturellen Erbes (Europas). Guest lecture at the IPMZ - Institute of Mass Communication and Media Research, Devision Media Change & Innovation, University of Zurich, Switzerland. (http://www.slideshare.net/em3rg3/digitalisierung-des-kulturellen-erbes-europa)

  15. Mécanique des fluides

    CERN Document Server

    Cengel, Y A

    2016-01-01

    La mécanique des fluides est un outil performant qui permet d'expliquer les phénomènes qui nous entourent de l'échelle microscopique à l'échelle macroscopique. Elle est aussi à la base du développement de nombreuses technologies. Cet ouvrage à destination des étudiants donne une vision complète de la mécanique des fluides. Bien que la mécanique des fluides puisse souvent paraître rébarbative aux yeux des étudiants, cet ouvrage valorise ce domaine d'enseignement en l'illustrant de nombreux exemples issus de l'ingénierie navale, l'aéronautique, la météorologie, etc.

  16. Characterization of organic membrane foulants in a forward osmosis membrane bioreactor treating anaerobic membrane bioreactor effluent.

    Science.gov (United States)

    Ding, Yi; Tian, Yu; Li, Zhipeng; Liu, Feng; You, Hong

    2014-09-01

    In this study, two aerobic forward osmosis (FO) membrane bioreactors (MBR) were utilized to treat the effluent of mesophilic (35°C) and atmospheric (25°C) anaerobic MBRs, respectively. The results showed that the FO membrane process could significantly improve the removal efficiencies of N and P. Meanwhile, the flux decline of the FOMBR treating effluent of mesophilic AnMBR (M-FOMBR) was higher than that treating effluent of atmospheric AnMBR (P-FOMBR). The organic membrane foulants in the two FOMBRs were analyzed to understand the membrane fouling behavior in FO processes. It was found that the slightly increased accumulation of protein-like substances into external foulants did not cause faster flux decline in P-FOMBR than that in M-FOMBR. However, the quantity of organic matter tended to deposit or adsorb into FO membrane pores in P-FOMBR was less than that in M-FOMBR, which was accordance with the tendency of membrane fouling indicated by flux decline.

  17. Characterization of organic membrane foulants in a forward osmosis membrane bioreactor treating anaerobic membrane bioreactor effluent.

    Science.gov (United States)

    Ding, Yi; Tian, Yu; Li, Zhipeng; Liu, Feng; You, Hong

    2014-09-01

    In this study, two aerobic forward osmosis (FO) membrane bioreactors (MBR) were utilized to treat the effluent of mesophilic (35°C) and atmospheric (25°C) anaerobic MBRs, respectively. The results showed that the FO membrane process could significantly improve the removal efficiencies of N and P. Meanwhile, the flux decline of the FOMBR treating effluent of mesophilic AnMBR (M-FOMBR) was higher than that treating effluent of atmospheric AnMBR (P-FOMBR). The organic membrane foulants in the two FOMBRs were analyzed to understand the membrane fouling behavior in FO processes. It was found that the slightly increased accumulation of protein-like substances into external foulants did not cause faster flux decline in P-FOMBR than that in M-FOMBR. However, the quantity of organic matter tended to deposit or adsorb into FO membrane pores in P-FOMBR was less than that in M-FOMBR, which was accordance with the tendency of membrane fouling indicated by flux decline. PMID:24976492

  18. Biodegradation of Trichloroethylene in Continuous-Recycle Expanded-Bed Bioreactors

    OpenAIRE

    Phelps, T. J.; Niedzielski, J. J.; Schram, R M; Herbes, S. E.; White, D. C.

    1990-01-01

    Experimental bioreactors operated as recirculated closed systems were inoculated with bacterial cultures that utilized methane, propane, and tryptone-yeast extract as aerobic carbon and energy sources and degraded trichloroethylene (TCE). Up to 95% removal of TCE was observed after 5 days of incubation. Uninoculated bioreactors inhibited with 0.5% Formalin and 0.2% sodium azide retained greater than 95% of their TCE after 20 days. Each bioreactor consisted of an expanded-bed column through wh...

  19. Fluidized-bed bioreactor system for the microbial solubilization of coal

    Science.gov (United States)

    Scott, C.D.; Strandberg, G.W.

    1987-09-14

    A fluidized-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fluidized-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fluidized-bed bioreactor. 2 figs.

  20. Fixed-bed bioreactor system for the microbial solubilization of coal

    Science.gov (United States)

    Scott, C.D.; Strandberg, G.W.

    1987-09-14

    A fixed-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fixed-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the large scale production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fixed-bed bioreactor. 1 fig., 1 tab.

  1. Fluidized-bed bioreactor process for the microbial solubiliztion of coal

    Science.gov (United States)

    Scott, Charles D.; Strandberg, Gerald W.

    1989-01-01

    A fluidized-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fluidized-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fluidized-bed bioreactor.

  2. An Update to Space Biomedical Research: Tissue Engineering in Microgravity Bioreactors

    OpenAIRE

    Abolfazl Barzegari; Amir Ata Saei

    2012-01-01

    Introduction: The severe need for constructing replacement tissues in organ transplantation has necessitated the development of tissue engineering approaches and bioreactors that can bring these approaches to reality. The inherent limitations of conventional bioreactors in generating realistic tissue constructs led to the devise of the microgravity tissue engineering that uses Rotating Wall Vessel (RWV) bioreactors initially developed by NASA. Methods: In this review article, we intend to hig...

  3. Sludge Bulking Property of Membrane Bio-reactor in Albumen Wqastewater Treatment

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Albumen wastewater was treated by Membrane Bio-reactor. Sludge bulking property of Membrane Bio-Reactor was investigated in this study through contrast research. When the sludge bulking appeared, the removal efficiency of COD in Membrane Bio-reactor increased slightly under the function of filamentous bacteria. However, the negative effects of the higher net water-head differential pressures,the higher block rate of membrane pore and the great quantity of filamentous bacteria at the externalsurface pres...

  4. Therapie des Status epilepticus

    Directory of Open Access Journals (Sweden)

    Trinka E

    2009-01-01

    Full Text Available Der Status epilepticus (SE ist nach dem Schlaganfall der häufigste neurologische Notfall. Er stellt als generaliserter konvulsiver SE (GKSE die schwerste Ausprägung eines epileptischen Anfalls dar, der mit einer signifikanten Morbidität und einer ca. 20%igen Letalität verbunden ist. Nur bei der Hälfte der Patienten mit SE besteht zuvor eine Epilepsie; die meisten Fälle sind symptomatisch, wobei Schädel- Hirn-Traumata, zerebrovaskuläre Erkrankungen, ZNS-Infektionen und metabolische Ursachen führend sind. Bei Patienten mit vorbestehender Epilepsie lässt sich eine frühe Phase des GKSE erkennen, in der die Anfälle crescendoartig zunehmen, bis sie in kontinuierliche Anfallsaktivität münden (etablierte Phase. Das Management eines GKSE verlangt rasches und beherztes Vorgehen. Neben der sofort einzuleitenden Therapie muss gleichzeitig die artdiagnostische Zuordnung des SE und die Ursache erkannt und behandelt werden. Als Therapie der ersten Wahl sind Benzodiazepine etabliert, wobei intravenösem (i.v. Lorazepam gegenüber Diazepam der Vorzug zu geben ist. Versagt die Therapie mit Benzodiazepinen, muss rasch und konsequent nach einem Stufenschema vorgegangen werden. Phenytoin/Fosphenytoin, Valproinsäure, Levetiracetam und Lacosamid sind als i.v. Formulierung erhältliche Antiepileptika. Obwohl Vergleichsstudien hier fehlen, wird Phenytoin bevorzugt. Valproat und Levetiracetam sind nicht sedierend und kardiovaskulär gut verträglich, sodass hier Alternativen zu Phenytoin vorhanden sind. Lacosamid ist eine neue Therapieoption, deren Stellenwert erst bestimmt werden muss. Versagt auch die zweite Therapiestufe, so muss der Patient intubiert und in Allgemeinanästhesie intensivmedizinisch behandelt werden. Dafür stehen Thiopental, Propofol oder hoch dosiertes Midazolam zu Verfügung. Durch den eklatanten Mangel an randomisierten Studien bleibt die Therapie des GKSE empirisch und durch den Off-label-Einsatz gekennzeichnet.

  5. Liste des auteurs

    OpenAIRE

    2015-01-01

    Yves Tanguy, Université de Nantes, France Jacques Verger, Université Paris Sorbonne, Paris, France Jéremy duQuesnay Adams, Dept of History, SMU, USA Étienne Wolff, Université de Paris X­Nanterre, France Claire Nouvet, Emory University, USA François Lejeune, Université de Nantes, France Wim Verbaal, Université de Gand, Belgique Thomas N. Bisson, Harvard University, USA Jean Jolivet, École Pratique des Hautes Études, Paris, France Guy Lobrichon, Collège de France, France Constant J. Mews, Sc...

  6. Bibliographie des expositions

    Directory of Open Access Journals (Sweden)

    Eléonore Fournié

    2009-09-01

    Full Text Available Autun, 1985Le Livre au siècle des Rolin, sous la dir. de Marie-Josette Perrat, Autun, Bibliothèque municipale, 8 juin-28 septembre 1985. Baltimore, 2002The Book of Kings: Art, War and the Morgan Library's Medieval Picture Bible, Baltimore, Walter Art Museum, 27 octobre-29 décembre 2002, Baltimore, Third Millennium Publishing, 2002. Bruxelles, 1937Les manuscrits à miniatures, du viiie siècle à 1350, Bruxelles, Bibliothèque royale de Belgique, 1937. Bruxelles, 1940La Bibliothèque de Marguerite ...

  7. Liste des figures

    OpenAIRE

    2013-01-01

    Illustrations dans le texte Villes italiennes 1. Plan de Naples en 1560. Source : Bibliothèque nationale de France, cliché BNF …………………… 8 2. Plan du nouveau tracé des rioni de Rome (1744). Source : Bernardino Bernardini, Descrizione del nuovo ripartimento de’ Rioni di Roma fatto pet ordine di N.S. Papa Benedetto XIV. Con la Notizia di quanto in essi si contiene, Rome, per Generoso Salomone, 1744, p. 225. Bibliothèque nationale de France, cliché BNF ……. 26 3. Détail du plan du quartiere de S. ...

  8. Des ignames au riz

    OpenAIRE

    Ivanoff, Jacques

    2003-01-01

    L'igname a toujours été une nourriture importante pour les populations littorales et nomades du monde insulindien. Cependant, avec l'installation du héros civilisateur Gaman le Malais chez le peuple de la reine Sibian, le riz va devenir la composante essentielle des repas moken. En intégrant Gaman en son sein, la société moken va devoir répondre au double défi posé par la menace de la riziculture et de l'islam. En donnant femme à Gaman, en adoptant le nomadisme pour échapper à l'islam ...

  9. Universos (Des) conocidos

    OpenAIRE

    Gutiérrez Vásquez, Martín Kanek

    2014-01-01

    Universos (Des) conocidos es un proyecto de creación plástica. Tiene como objetivo la construcción de imágenes poéticas sobre el universo, las estrellas y nuestra relación como humanos con ellas. El proceso consintió en conformar durante 2 años un archivo de objetos recolectados de la calle, para después construir esculturas que fueron quemadas en un acto ritual. Al final se presentó los restos quemados de las esculturas, a la par se presentaban videos del registro junto con 4 afiches q...

  10. Der Preis des Reiches

    OpenAIRE

    Wilker, Julia

    2015-01-01

    Wie schon die meisten hellenistischen Könige zeichneten sich auch die römischen Klientelherrscher in der Zeit des frühen Prinzipat durch Stitungen und Spenden an Städte, Gemeinden und Heiligtümer außerhalb ihrer eigenen Herrschatsgebiete aus. Jedoch zeigt eine genauere Analyse der Stitungsempfänger, der Verteilung und Art ihrer Gaben, dass es bei der euergetischen Praxis der Klientelherrscher nicht um eine einfach Imitation oder Fortsetzung überlebter monarchischer Traditionen ging, sond...

  11. High-throughput miniaturized bioreactors for cell culture process development: reproducibility, scalability, and control.

    Science.gov (United States)

    Rameez, Shahid; Mostafa, Sigma S; Miller, Christopher; Shukla, Abhinav A

    2014-01-01

    Decreasing the timeframe for cell culture process development has been a key goal toward accelerating biopharmaceutical development. Advanced Microscale Bioreactors (ambr™) is an automated micro-bioreactor system with miniature single-use bioreactors with a 10-15 mL working volume controlled by an automated workstation. This system was compared to conventional bioreactor systems in terms of its performance for the production of a monoclonal antibody in a recombinant Chinese Hamster Ovary cell line. The miniaturized bioreactor system was found to produce cell culture profiles that matched across scales to 3 L, 15 L, and 200 L stirred tank bioreactors. The processes used in this article involve complex feed formulations, perturbations, and strict process control within the design space, which are in-line with processes used for commercial scale manufacturing of biopharmaceuticals. Changes to important process parameters in ambr™ resulted in predictable cell growth, viability and titer changes, which were in good agreement to data from the conventional larger scale bioreactors. ambr™ was found to successfully reproduce variations in temperature, dissolved oxygen (DO), and pH conditions similar to the larger bioreactor systems. Additionally, the miniature bioreactors were found to react well to perturbations in pH and DO through adjustments to the Proportional and Integral control loop. The data presented here demonstrates the utility of the ambr™ system as a high throughput system for cell culture process development.

  12. Optimization of biological sulfide removal in a CSTR bioreactor.

    Science.gov (United States)

    Roosta, Aliakbar; Jahanmiri, Abdolhossein; Mowla, Dariush; Niazi, Ali; Sotoodeh, Hamidreza

    2012-08-01

    In this study, biological sulfide removal from natural gas in a continuous bioreactor is investigated for estimation of the optimal operational parameters. According to the carried out reactions, sulfide can be converted to elemental sulfur, sulfate, thiosulfate, and polysulfide, of which elemental sulfur is the desired product. A mathematical model is developed and was used for investigation of the effect of various parameters on elemental sulfur selectivity. The results of the simulation show that elemental sulfur selectivity is a function of dissolved oxygen, sulfide load, pH, and concentration of bacteria. Optimal parameter values are calculated for maximum elemental sulfur selectivity by using genetic algorithm as an adaptive heuristic search. In the optimal conditions, 87.76% of sulfide loaded to the bioreactor is converted to elemental sulfur.

  13. Embryoid body formation: recent advances in automated bioreactor technology.

    Science.gov (United States)

    Trettner, Susanne; Seeliger, Alexander; zur Nieden, Nicole I

    2011-01-01

    While spontaneous differentiation is an undesired feature of expanding populations of embryonic stem cells, a variety of methods have been described for their intended differentiation into specialized cell types, such as the osteoblast or chondrocyte. Most commonly, differentiation initiation involves the aggregation of ESCs into a so-called embryoid body (EB), a sphere composed of approximately 15,000 differentiating cells. EB formation has been optimized through the years, for example through invention of the hanging drop protocol. Yet, it remains a highly laborious process. Here we describe the use of computer-controllable suspension bioreactors to form EBs in an automated and highly reproducible process and their subsequent differentiation along the osteoblast lineage. The development of the differentiating cells taken from bioreactor EBs to EBs formed in static control cultures through the hanging drop method will be compared. PMID:21042990

  14. Sanitary Sewage Treatment with Jet Inner-loop Bioreactor

    Institute of Scientific and Technical Information of China (English)

    Wen Qin-xue; Chen Zhi-qiang; Lu Bing-nan; Wen Yan

    2004-01-01

    A jet inncr-loop bioreactor (JIBR) was used to treat synthetic sanitary sewage with low, medium and high COD load. The experimental resuhs show that it could meet discharge standard at 20-30 min of HRT (hydraulic retention time) for low COD concentration and 60-120 min of HRT for medium and high COD concentration. The maximal COD volume loading and COD sludye loading of 27kg·m-3·d-1 and 5 kg/d per kg MLSS were achieved respectively, that were 10-20 times higher than those of traditional wastewater treatment processes. The BOD5 removal efficiency was more than 90 % and NH1-N more than 85 %. The study on the activity showed that the oxygen consumption rate of the activated times higher than that of the SBR(Sequencing Batch Reactor)and thc dominant bacteria in jet inner-loop bioreactor was Pseudomonas species.

  15. Hydrodynamic characterization of a column-type prototype bioreactor.

    Science.gov (United States)

    Espinosa-Solares, Teodoro; Morales-Contreras, Marcos; Robles-Martínez, Fabián; García-Nazariega, Melvin; Lobato-Calleros, Consuelo

    2008-03-01

    Agro-food industrial processes produce a large amount of residues, most of which are organic. One of the possible solutions for the treatment of these residues is anaerobic digestion in bioreactors. A novel 18-L bioreactor for treating waste water was designed based on pneumatic agitation and semispherical baffles. Flow patterns were visualized using the particle tracer technique. Circulation times were measured with the particle tracer and the thermal technique, while mixing times were measured using the thermal technique. Newtonian fluid and two non-Newtonian fluids were used to simulate the operational conditions. The results showed that the change from Newtonian to non-Newtonian properties reduces mixed zones and increases circulation and mixing times. Circulation time was similar when evaluated with the thermal and the tracer particle methods. It was possible to predict dimensionless mixing time (theta (m)) using an equivalent Froude number (Fr (eq)). PMID:18401759

  16. Characteristics, Process Parameters, and Inner Components of Anaerobic Bioreactors

    Science.gov (United States)

    Abdelgadir, Awad; Chen, Xiaoguang; Liu, Jianshe; Xie, Xuehui; Zhang, Jian; Zhang, Kai; Wang, Heng; Liu, Na

    2014-01-01

    The anaerobic bioreactor applies the principles of biotechnology and microbiology, and nowadays it has been used widely in the wastewater treatment plants due to their high efficiency, low energy use, and green energy generation. Advantages and disadvantages of anaerobic process were shown, and three main characteristics of anaerobic bioreactor (AB), namely, inhomogeneous system, time instability, and space instability were also discussed in this work. For high efficiency of wastewater treatment, the process parameters of anaerobic digestion, such as temperature, pH, Hydraulic retention time (HRT), Organic Loading Rate (OLR), and sludge retention time (SRT) were introduced to take into account the optimum conditions for living, growth, and multiplication of bacteria. The inner components, which can improve SRT, and even enhance mass transfer, were also explained and have been divided into transverse inner components, longitudinal inner components, and biofilm-packing material. At last, the newly developed special inner components were discussed and found more efficient and productive. PMID:24672798

  17. Biological nitrogen removal using a submerged membrane bioreactor system

    International Nuclear Information System (INIS)

    A pilot-scale study was conducted using ZenoGem hollow-fiber microfiltration membrane bioreactor system to investigate the performance of membrane bioreactor process to remove nitrogen from primary effluent at a municipal wastewater treatment plant. Different operating conditions were examined by varying hydraulic retention time (HRT) and sludge retention time (SRT) between 5-8 h and 20-50 days, respectively. In addition, a series of laboratory batch tests were performed to measure the biodegradation kinetic and stoichiometric parameters under the conditions consistent with the pilot testing. The results showed that the process achieved removal efficiencies of 80-98% for COD, 93%-99% for BOD5, and 70-93% for nitrogen. The efficiency and kinetics of COD and nitrogen removal would change greatly from one operating condition to another. However, the measured kinetic parameters still fell within the typical range of those reported in the literature using Activated Sludge Models (ASM)

  18. Molekulare Formen des PSA in der Diagnostik des Prostatakarzinoms

    Directory of Open Access Journals (Sweden)

    Lein M

    2003-01-01

    Full Text Available Das prostataspezifische Antigen ist die wichtigste Kenngröße in der Diagnostik und Therapieüberwachung des Prostatakarzinoms. Zur besseren Abgrenzung zwischen Männern mit und ohne Prostatakarzinom, aber auch zur Früherkennung, haben sich die molekularen Formen des PSA als wertvolle Entscheidungshilfen erwiesen. Es wird eine Übersicht über bisher vorliegende Informationen zur Aussagekraft des freien PSA, des an alpha 1-Antichymotrypsin gebundenen PSA und des komplexierten PSA (cPSA zusammen mit eigenen Resultaten gegeben. Der Quotient aus freiem und Gesamt-PSA hat sich als eine wichtige Entscheidungsgröße in der urologischen Praxis etabliert, mit der Sensitivität und Spezifität der Prostatakarzinomdiagnostik verbessert werden. Die Zahl von Prostatastanzbiopsien im Gesamt-PSA-Bereich von 4–10 ng/ml kann damit reduziert werden. Ein diagnostischer Vorteil der alleinigen Bestimmung des komplexierten PSA bzw. der entsprechenden Quotienten im Vergleich zum Gesamt-PSA und des Quotienten freies PSA zu Gesamt-PSA konnte bisher nicht sicher nachgewiesen werden.

  19. Mécanique des sols et des roches

    CERN Document Server

    Vullier, Laurent; Zhao, Jian

    2016-01-01

    La mécanique des sols et la mécanique des roches sont des disciplines généralement traitées séparément dans la littérature. Pour la première fois, un traité réunit ces deux spécialités, en intégrant également les connaissances en lien avec les écoulements souterrains et les transferts thermiques. A la fois théorique et pratique, cet ouvrage propose tout d'abord une description détaillée de la nature et de la composition des sols et des roches, puis s'attache à la modélisation de problèmes aux conditions limites et présente les essais permettant de caractériser les sols et les roches, tant d'un point de vue mécanique qu'hydraulique et thermique. La problématique des sols non saturés et des écoulements multiphasiques est également abordée. Une attention particulière est portée aux lois de comportement mécanique et à la détermination de leurs paramètres par des essais in situ et en laboratoire, et l'ouvrage offre également une présentation détaillée des systèmes de classi...

  20. The Potential for Microalgae as Bioreactors to Produce Pharmaceuticals

    OpenAIRE

    Na Yan; Chengming Fan; Yuhong Chen; Zanmin Hu

    2016-01-01

    As photosynthetic organisms, microalgae can efficiently convert solar energy into biomass. Microalgae are currently used as an important source of valuable natural biologically active molecules, such as carotenoids, chlorophyll, long-chain polyunsaturated fatty acids, phycobiliproteins, carotenoids and enzymes. Significant advances have been achieved in microalgae biotechnology over the last decade, and the use of microalgae as bioreactors for expressing recombinant proteins is receiving incr...

  1. Liquid circulation in external-loop airlift bioreactors.

    Science.gov (United States)

    Kawase, Y

    1990-03-01

    A simple model for prediction of liquid velocity in external-loop airlift bioreactors has been developed. Theoretical correlations for friction factor of gas-non-Newtonian two-phase flows and for liquid velocity in the riser were derived using the concept of an eddy diffusivity. The predictions of the proposed model were compared with the available experimental data for the friction factor and the liquid velocity in the riser of external-loop airlift contactors. Satisfactory agreement was obtained.

  2. Micropollutants removal and tecnological development of membrane bioreactors

    OpenAIRE

    Santos, Ana

    2010-01-01

    The increasing worldwide contamination of aquatic environment with pollutants introduced by anthropogenic sources has become of great concern. Although present at low concentration, many of these pollutants have considerable long-term impacts on the ecosystem, such that extremely challenging legislative limits on their concentration in effluents are being proposed. This has led to the examination of membrane bioreactor (MBR) technology for wastewater treatment, since it offers ...

  3. Startup and stabilization of anaerobic membrane bioreactors at ambient temperature

    OpenAIRE

    Benito Peña, Carlos

    2015-01-01

    There has been an increasing interest in wastewater treatment in last decades to reduce human footprint. Primarily, anaerobic technology focused on treatment and stabilization of sludge, but now the tendency is to give it a major role in low cost treatment of high/low strength wastewaters, since anaerobic digestion offers energy generation through gas production. Anaerobic membrane bioreactors (AnMBR) combine anaerobic digestion with membrane filtration. They are becoming a feasible opti...

  4. Cytotoxicity micropollutant removal in a crossflow membrane bioreactor

    OpenAIRE

    Delgado, Luis Fernando; Faucet-Marquis, Virginie; Pfohl-Leszkowicz, Annie; Dorandeu, Christophe; Marion, Bénédicte; Schetrite, Sylvie; Albasi, Claire

    2011-01-01

    The application of membrane bioreactor (MBR) technology was investigated with the aim of evaluating its potential for cytostatic drug and cytotoxicity bioremoval. The toxicity removal was assessed from biomarker test. CP removal of up to 80% was achieved under the operating conditions studied (HRT of 48 h and a SRT of 50 days). The increase of TMP was associated with an increase of supernatant toxicity as if fouling led to retention of the toxicity. Peaks of supernatant cytotoxicity were corr...

  5. Analysis of fouling mechanisms in anaerobic membrane bioreactors

    OpenAIRE

    Charfi, Amine; Ben Amar, Nihel; Harmand, Jérôme

    2012-01-01

    In this paper, we investigate the fouling mechanisms responsible for MF and UF membrane flux decline in Anaerobic Membrane Bioreactors (AnMBR). We have used the fouling mechanism models proposed by Hermia (1982), namely pore constriction, cake formation, complete blocking and intermediate blocking. Based on an optimization approach and using experimental data extracted from the literature, we propose a systematic procedure for identifying the most likely fouling mechanism in play. Short-term ...

  6. Anaerobic membrane bioreactors for wastewater treatment: feasibility and potential applications

    OpenAIRE

    Jeison, D.A.

    2007-01-01

    Biomass retention is a necessary feature for the successful application of anaerobic digestion for wastewater treatment. Biofilms and granule formation are the traditional way to achieve such retention, enabling reactor operation at high biomass concentrations, and therefore at high organic loading rates. Membrane filtration represents an alternative way to achieve biomass retention. In membrane bioreactors, complete biomass retention can be achieved, irrespective of cells capacity to form bi...

  7. Biogas Production from Citrus Waste by Membrane Bioreactor

    OpenAIRE

    Rachma Wikandari; Ria Millati; Muhammad Nur Cahyanto2); Taherzadeh, Mohammad J.

    2014-01-01

    Rapid acidification and inhibition by d-limonene are major challenges of biogas production from citrus waste. As limonene is a hydrophobic chemical, this challenge was encountered using hydrophilic polyvinylidine difluoride (PVDF) membranes in a biogas reactor. The more sensitive methane-producing archaea were encapsulated in the membranes, while freely suspended digesting bacteria were present in the culture as well. In this membrane bioreactor (MBR), the free digesting bacteria digested the...

  8. A Novel Seeding and Conditioning Bioreactor for Vascular Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Julia Schulte

    2014-07-01

    Full Text Available Multiple efforts have been made to develop small-diameter tissue engineered vascular grafts using a great variety of bioreactor systems at different steps of processing. Nevertheless, there is still an extensive need for a compact all-in-one system providing multiple and simultaneous processing. The aim of this project was to develop a new device to fulfill the major requirements of an ideal system that allows simultaneous seeding, conditioning, and perfusion. The newly developed system can be actuated in a common incubator and consists of six components: a rotating cylinder, a pump, a pulse generator, a control unit, a mixer, and a reservoir. Components that are in direct contact with cell media, cells, and/or tissue allow sterile processing. Proof-of-concept experiments were performed with polyurethane tubes and collagen tubes. The scaffolds were seeded with fibroblasts and endothelial cells that were isolated from human saphenous vein segments. Scanning electron microscopy and immunohistochemistry showed better seeding success of polyurethane scaffolds in comparison to collagen. Conditioning of polyurethane tubes with 100 dyn/cm2 resulted in cell detachments, whereas a moderate conditioning program with stepwise increase of shear stress from 10 to 40 dyn/cm2 induced a stable and confluent cell layer. The new bioreactor is a powerful tool for quick and easy testing of various scaffold materials for the development of tissue engineered vascular grafts. The combination of this bioreactor with native tissue allows testing of medical devices and medicinal substances under physiological conditions that is a good step towards reduction of animal testing. In the long run, the bioreactor could turn out to produce tissue engineered vascular grafts for human applications “at the bedside”.

  9. Mathematical interpretation of mass transfer process in anaerobic bioreactors

    OpenAIRE

    Ружинская, Людмила Ивановна; Фоменкова, Анастасия Алексеевна

    2013-01-01

    The article considers the methanogenesis in bioreactors with immobilized microflora on fixed media. The processes of decomposition of organic pollution of the wastewater and the formation of metabolic products are analyzed. At the same time, the decomposition of organic pollution is considered from the standpoint of a two-stage process. As the first stage, the hydrolysis and acid production is considered, as the second - methanogenesis. On the basis of this process the spatial distribution of...

  10. Denitrification 'Woodchip' Bioreactors for Productive and Sustainable Agricultural Systems

    Science.gov (United States)

    Christianson, L. E.; Summerfelt, S.; Sharrer, K.; Lepine, C.; Helmers, M. J.

    2014-12-01

    Growing alarm about negative cascading effects of reactive nitrogen in the environment has led to multifaceted efforts to address elevated nitrate-nitrogen levels in water bodies worldwide. The best way to mitigate N-related impacts, such as hypoxic zones and human health concerns, is to convert nitrate to stable, non-reactive dinitrogen gas through the natural process of denitrification. This means denitrification technologies need to be one of our major strategies for tackling the grand challenge of managing human-induced changes to our global nitrogen cycle. While denitrification technologies have historically been focused on wastewater treatment, there is great interest in new lower-tech options for treating effluent and drainage water from one of our largest reactive nitrogen emitters -- agriculture. Denitrification 'woodchip' bioreactors are able to enhance this natural N-conversion via addition of a solid carbon source (e.g., woodchips) and through designs that facilitate development of anoxic conditions required for denitrification. Wood-based denitrification technologies such as woodchip bioreactors and 'sawdust' walls for groundwater have been shown to be effective at reducing nitrate loads in agricultural settings around the world. Designing these systems to be low-maintenance and to avoid removing land from agricultural production has been a primary focus of this "farmer-friendly" technology. This presentation provides a background on woodchip bioreactors including design considerations, N-removal performance, and current research worldwide. Woodchip bioreactors for the agricultural sector are an accessible new option to address society's interest in improving water quality while simultaneously allowing highly productive agricultural systems to continue to provide food in the face of increasing demand, changing global diets, and fluctuating weather.

  11. An expert system based intelligent control scheme for space bioreactors

    Science.gov (United States)

    San, Ka-Yiu

    1988-01-01

    An expert system based intelligent control scheme is being developed for the effective control and full automation of bioreactor systems in space. The scheme developed will have the capability to capture information from various resources including heuristic information from process researchers and operators. The knowledge base of the expert system should contain enough expertise to perform on-line system identification and thus be able to adapt the controllers accordingly with minimal human supervision.

  12. Bioreactors for tissue engineering--a new role for perfusionists?

    Science.gov (United States)

    Sistino, Joseph J

    2003-09-01

    Tissue engineering is an exciting new area of medicine with rapid growth and expansion over the last decade. It has the potential to have a profound impact on the practice of medicine and influence the economic development in the industry of biotechnology. In almost every specialty of medicine, the ability to generate replacement cells and develop tissues will change the focus from artificial organs and transplantation to growing replacement organs from the patient's own stem cells. Once these organs are at a size that requires perfusion to maintain oxygen and nutrient delivery, then automated perfusion systems termed "bioreactors" will be necessary to sustain the organ until harvesting. The design of these "bioreactors" will have a crucial role in the maintenance of cellular function throughout the growth period. The perfusion schemes necessary to determine the optimal conditions have not been well elucidated and will undergo extensive research over the next decade. The key to progress in this endeavor will development of long-term perfusion techniques and identifying the ideal pressures, flow rates, type of flow (pulsatile/nonpulsatile), and perfusate solution. Perfusionists are considered experts in the field of whole body perfusion, and it is possible that they can participate in the development and operation of these "bioreactors." Additional education of perfusionists in the area of tissue engineering is necessary in order for them to become integral parts of this exciting new area of medicine.

  13. Biogas Production from Citrus Waste by Membrane Bioreactor

    Directory of Open Access Journals (Sweden)

    Rachma Wikandari

    2014-08-01

    Full Text Available Rapid acidification and inhibition by d-limonene are major challenges of biogas production from citrus waste. As limonene is a hydrophobic chemical, this challenge was encountered using hydrophilic polyvinylidine difluoride (PVDF membranes in a biogas reactor. The more sensitive methane-producing archaea were encapsulated in the membranes, while freely suspended digesting bacteria were present in the culture as well. In this membrane bioreactor (MBR, the free digesting bacteria digested the citrus wastes and produced soluble compounds, which could pass through the membrane and converted to biogas by the encapsulated cell. As a control experiment, similar digestions were carried out in bioreactors containing the identical amount of just free cells. The experiments were carried out in thermophilic conditions at 55 °C, and hydraulic retention time of 30 days. The organic loading rate (OLR was started with 0.3 kg VS/m3/day and gradually increased to 3 kg VS/m3/day. The results show that at the highest OLR, MBR was successful to produce methane at 0.33 Nm3/kg VS, while the traditional free cell reactor reduced its methane production to 0.05 Nm3/kg VS. Approximately 73% of the theoretical methane yield was achieved using the membrane bioreactor.

  14. Biogas production from citrus waste by membrane bioreactor.

    Science.gov (United States)

    Wikandari, Rachma; Millati, Ria; Cahyanto, Muhammad Nur; Taherzadeh, Mohammad J

    2014-01-01

    Rapid acidification and inhibition by d-limonene are major challenges of biogas production from citrus waste. As limonene is a hydrophobic chemical, this challenge was encountered using hydrophilic polyvinylidine difluoride (PVDF) membranes in a biogas reactor. The more sensitive methane-producing archaea were encapsulated in the membranes, while freely suspended digesting bacteria were present in the culture as well. In this membrane bioreactor (MBR), the free digesting bacteria digested the citrus wastes and produced soluble compounds, which could pass through the membrane and converted to biogas by the encapsulated cell. As a control experiment, similar digestions were carried out in bioreactors containing the identical amount of just free cells. The experiments were carried out in thermophilic conditions at 55 °C, and hydraulic retention time of 30 days. The organic loading rate (OLR) was started with 0.3 kg VS/m3/day and gradually increased to 3 kg VS/m3/day. The results show that at the highest OLR, MBR was successful to produce methane at 0.33 Nm3/kg VS, while the traditional free cell reactor reduced its methane production to 0.05 Nm3/kg VS. Approximately 73% of the theoretical methane yield was achieved using the membrane bioreactor. PMID:25167328

  15. Immunological analysis of aerobic bioreactor bovine theileriosis vaccine.

    Directory of Open Access Journals (Sweden)

    Gholamreza Habibi

    2014-09-01

    Full Text Available In this study, the pilot production of aerobic bioreactor tropical theileriosis vaccine was optimized with the aim of immunological assays for further mass production.We have shown earlier the delayed type hypersensitivity (DTH assay could be used for evaluating the immunity and memory cells against specific Theileria antigen in vaccinated animals. In addition, TNF-α is the principle cytokine in modulating the cytotoxic activity of cytotoxic T-lymphocytes (CTL. Immunological analysis of the vaccine was performed by using two cell mediated immunity (CMI in vitro and in vivo DTH test (Theilerin and TNF-α assay.The results of immune responses of susceptible immunized cattle by bioreactor vaccine in comparison with conventional flask vaccine revealed a significant stimulation of immune cells by transcription of high level of TNF-α and positive reaction against Theileria antigen in Theilerin skin test (DTH.The equal immunological results achieved in both above mentioned vaccines verified the satisfactory immunity for aerobic bioreactor theileriosis vaccine for advance mass vaccination in the field on a large-scale.

  16. Denitrifying Bioreactors for Nitrate Removal: A Meta-Analysis.

    Science.gov (United States)

    Addy, Kelly; Gold, Arthur J; Christianson, Laura E; David, Mark B; Schipper, Louis A; Ratigan, Nicole A

    2016-05-01

    Meta-analysis approaches were used in this first quantitative synthesis of denitrifying woodchip bioreactors. Nitrate removal across environmental and design conditions was assessed from 26 published studies, representing 57 separate bioreactor units (i.e., walls, beds, and laboratory columns). Effect size calculations weighted the data based on variance and number of measurements for each bioreactor unit. Nitrate removal rates in bed and column studies were not significantly different, but both were significantly higher than wall studies. In denitrifying beds, wood source did not significantly affect nitrate removal rates. Nitrate removal (mass per volume) was significantly lower in beds with effects with bed temperature; a of 2.15 was quite similar to other studies. Lessons from this meta-analysis can be incorporated into bed designs, especially extending hydraulic retention times to increase nitrate removal under low temperature and high flow conditions. Additional column studies are warranted for comparative assessments, as are field-based studies for assessing in situ conditions, especially in aging beds, with careful collection and reporting of design and environmental data. Future assessment of these systems might take a holistic view, reviewing nitrate removal in conjunction with other processes, including greenhouse gas and other unfavorable by-product production. PMID:27136153

  17. Simulation of three-phase fluidized bioreactors for denitrification

    International Nuclear Information System (INIS)

    Fluidized-bed bioreactors were developed and operated at three scales (diameters of 0.1, 0.2, and 0.5 m) by the Chemical Technology Division. The performance of these reactors in denitrification was simulated using the following modified form of Monod kinetics to describe the reaction kinetics: rate = V/sub max/ (NO3-/K/sub s/ + NO3-) (% biomass). In the fluids-movement portion of the simulation the tanks-in-series approximation to backmixing was used. This approach yielded a V/sub max/ of 3.5 g/m3-min (% biomass) and a K/sub s/ of 163 g/m3 for the 0.5-m bioreactor. Values of V/sub max/ and K/sub s/ were also determined for data derived from the 0.1-m bioreactor, but inadequate RTD data reduced the confidence level in these results. A complication in denitrification is the multi-step nature of the reduction from nitrate to nitrite to hyponitrite and finally to nitrogen. An experimental study of the effect of biomass loading upon denitrification was begun. It is recommended that the experimental work be continued

  18. Therapie des abdominellen Aortenaneurysmas

    Directory of Open Access Journals (Sweden)

    Rieß HC

    2014-01-01

    Full Text Available Zur invasiven elektiven und notfallmäßigen Therapie des abdominellen Aortenaneurysmas steht vor allem das offen-chirurgische und das endovaskuläre Verfahren zur Verfügung. Aufgrund einer deutlich erhöhten Mortalitätsrate im rupturierten Stadium sollte dabei stets ein elektives Vorgehen angestrebt werden. Die rechtzeitige Identifizierung erkrankter Patienten im asymptomatischen Stadium, beispielsweise im Rahmen eines Aortenscreenings für Risikogruppen, ist aus diesem Grund von größter Wichtigkeit. Trotz mehrerer randomisierter Studien zu den genannten Therapieoptionen kann bis heute keine vereinfachende Therapieempfehlung für eines der beiden konkurrierenden Verfahren ausgesprochen werden. Die Indikationsstellung erfordert stets eine sehr differenzierte Berücksichtigung aller eingehenden Faktoren. Auch ohne eine klare Empfehlung hat die endovaskuläre Versorgung des Aortenaneurysmas in vielen Ländern, so auch in Deutschland, bereits einen Anteil von über 50 % erlangt. Die kontinuierliche Verbesserung von Verfahren und Material spiegelt sich in einer signifikant kürzeren Krankenhausverweildauer und in einer niedrigeren Letalität der EVAR bei hohen technischen Erfolgsraten wider. Im Hinblick auf Langzeitergebnisse profitieren heute überwiegend ältere Personen von einer endovaskulären Aneurysma-Ausschaltung, für die aufgrund eines hohen OP-Risikos eine offen-chirurgische Versorgung nicht in Frage kommt. Zukünftig werden, bei einem vergleichbaren Outcome beider Verfahren, auch gesundheitsökonomische Aspekte eine Rolle spielen und in die Empfehlungen eingehen.

  19. A novel bioreactor to simulate urinary bladder mechanical properties and compliance for bladder functional tissue engineering

    Institute of Scientific and Technical Information of China (English)

    WEI Xin; LI Dao-bing; XU Feng; WANG Yan; ZHU Yu-chun; LI Hong; WANG Kun-jie

    2011-01-01

    Background Bioreactors are pivotal tools for generating mechanical stimulation in functional tissue engineering study.This study aimed to create a bioreactor that can simulate urinary bladder mechanical properties, and to investigate the effects of a mechanically stimulated culture on urothelial cells and bladder smooth muscle cells.Methods We designed a bioreactor to simulate the mechanical properties of bladder. A pressure-record system was used to evaluate the mechanical properties of the bioreactor by measuring the pressure in culture chambers. To test the biocompatibility of the bioreactor, viabilities of urothelial cells and smooth muscle cells cultured in the bioreactor under static and mechanically changed conditions were measured after 7-day culture. To evaluate the effect of mechanical stimulations on the vital cells, urethral cells and smooth muscle cells were cultured in the simulated mechanical conditions. After that, the viability and the distribution pattern of the cells were observed and compared with cells cultured in non-mechanical stimulated condition.Results The bioreactor system successfully generated waveforms similar to the intended programmed model while maintaining a cell-seeded elastic membrane between the chambers. There were no differences between viabilities of urothelial cells ((91.90±1.22)% vs. (93.14±1.78)%, P >0.05) and bladder smooth muscle cells ((93.41±1.49)% vs.(92.61±1.34)%, P >0.05). The viability of cells and tissue structure observation after cultured in simulated condition showed that mechanical stimulation was the only factor affected cells in the bioreactor and improved the arrangement of cells on silastic membrane.Conclusions This bioreactor can effectively simulate the physiological and mechanical properties of the bladder.Mechanical stimulation is the only factor that affected the viability of cells cultured in the bioreactor. The bioreactor can change the growth behavior of urothelial cells and bladder smooth

  20. Start-up of membrane bioreactor and hybrid moving bed biofilm reactor-membrane bioreactor: kinetic study.

    Science.gov (United States)

    Leyva-Díaz, J C; Poyatos, J M

    2015-01-01

    A hybrid moving bed biofilm reactor-membrane bioreactor (hybrid MBBR-MBR) system was studied as an alternative solution to conventional activated sludge processes and membrane bioreactors. This paper shows the results obtained from three laboratory-scale wastewater treatment plants working in parallel in the start-up and steady states. The first wastewater treatment plant was a MBR, the second one was a hybrid MBBR-MBR system containing carriers both in anoxic and aerobic zones of the bioreactor (hybrid MBBR-MBRa), and the last one was a hybrid MBBR-MBR system which contained carriers only in the aerobic zone (hybrid MBBR-MBRb). The reactors operated with a hydraulic retention time of 30.40 h. A kinetic study for characterizing heterotrophic biomass was carried out and organic matter and nutrients removals were evaluated. The heterotrophic biomass of the hybrid MBBR-MBRb showed the best kinetic performance in the steady state, with yield coefficient for heterotrophic biomass=0.30246 mg volatile suspended solids per mg chemical oxygen demand, maximum specific growth rate for heterotrophic biomass=0.00308 h(-1) and half-saturation coefficient for organic matter=3.54908 mg O2 L(-1). The removal of organic matter was supported by the kinetic study of heterotrophic biomass.

  1. Start-up of membrane bioreactor and hybrid moving bed biofilm reactor-membrane bioreactor: kinetic study.

    Science.gov (United States)

    Leyva-Díaz, J C; Poyatos, J M

    2015-01-01

    A hybrid moving bed biofilm reactor-membrane bioreactor (hybrid MBBR-MBR) system was studied as an alternative solution to conventional activated sludge processes and membrane bioreactors. This paper shows the results obtained from three laboratory-scale wastewater treatment plants working in parallel in the start-up and steady states. The first wastewater treatment plant was a MBR, the second one was a hybrid MBBR-MBR system containing carriers both in anoxic and aerobic zones of the bioreactor (hybrid MBBR-MBRa), and the last one was a hybrid MBBR-MBR system which contained carriers only in the aerobic zone (hybrid MBBR-MBRb). The reactors operated with a hydraulic retention time of 30.40 h. A kinetic study for characterizing heterotrophic biomass was carried out and organic matter and nutrients removals were evaluated. The heterotrophic biomass of the hybrid MBBR-MBRb showed the best kinetic performance in the steady state, with yield coefficient for heterotrophic biomass=0.30246 mg volatile suspended solids per mg chemical oxygen demand, maximum specific growth rate for heterotrophic biomass=0.00308 h(-1) and half-saturation coefficient for organic matter=3.54908 mg O2 L(-1). The removal of organic matter was supported by the kinetic study of heterotrophic biomass. PMID:26606088

  2. Effects of the addition of rape oil methyl ester (RME) on the lubrication performance of low-sulphur diesel fuel as specified in DIN EN 590 (new). Final report; Auswirkungen des Zusatzes von Rapsoelmethylester (RME) auf die Schmierfaehigkeit von schwefelarmem Dieselkraftstoff nach DIN EN 590 (neu). Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Prescher, K.; Wichmann, V.

    2001-06-01

    Pflanzenoelmethylester (PME), insbesondere Rapsoelmethylester (RME), gutes Eigenschmierverhalten besitzen und die Dauerstandfestigkeit von Dieselmotoren beim Betrieb mit RME gemaess Spezifikation als gesichert gilt, liegt es nahe, mit Zumischungen zum mineraloelbasierten Dieselkraftstoff synthetisch hergestellte und damit teure Additive oder Teile von ihnen zu ersetzen. An die Zuschlagstoffe (Additive) oder Zumischungen fuer Dieselkraftstoffe, die die guenstige Beeinflussung des Reibungs- und Verschleissverhaltens anstelle der Schwefelverbindungen uebernehmen muessen, werden hohe Anforderungen gestellt. Ziel der Untersuchungen ist es, die Eignung von RME und Sonnenblumenmethylester als Schmierstoffzusatz zum Dieselkraftstoff nachzuweisen. (orig.)

  3. Containerized Wetland Bioreactor Evaluated for Perchlorate and Nitrate Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Dibley, V R; Krauter, P W

    2004-12-02

    The U.S. Department of Energy (DOE) and Lawrence Livermore Laboratory (LLNL) designed and constructed an innovative containerized wetlands (bioreactor) system that began operation in November 2000 to biologically degrade perchlorate and nitrate under relatively low-flow conditions at a remote location at Site 300 known as Building 854. Since initial start-up, the system has processed over 3,463,000 liters of ground water and treated over 38 grams of perchlorate and 148 kilograms of nitrate. Site 300 is operated by the University of California as a high-explosives and materials testing facility supporting nuclear weapons research. The 11-square mile site located in northern California was added to the NPL in 1990 primarily due to the presence of elevated concentrations of volatile organic compounds (VOCs) in ground water. At the urging of the regulatory agencies, perchlorate was looked for and detected in the ground water in 1999. VOCs, nitrate and perchlorate were released into the soil and ground water in the Building 854 area as the result of accidental leaks during stability testing of weapons or from waste discharge practices that are no longer permitted at Site 300. Design of the wetland bioreactors was based on earlier studies showing that indigenous chlorate-respiring bacteria could effectively degrade perchlorate into nontoxic concentrations of chlorate, chlorite, oxygen, and chloride. Studies also showed that the addition of organic carbon would enhance microbial denitrification. Early onsite testing showed acetic acid to be a more effective carbon source than dried leaf matter, dried algae, or milk replacement starter; a nutrient and carbon source used in a Department of Defense phytoremediation demonstration. No inocula were added to the system. Groundwater was allowed to circulate through the bioreactor for three weeks to acclimate the wetland plants and to build a biofilm from indigenous flora. Using solar energy, ground water is pumped into granular

  4. Beeinflussung von Osteoblasten und Endothelzellen durch Zoledronat in vitro

    OpenAIRE

    Beckmann, E

    2014-01-01

    Zielsetzung: Um Hinweise zur Pathogenese der Bisphosphonat-assoziierten Osteonekrose im Kiefer (BP-ONJ) zu sammeln, wurden bovine Osteoblasten-ähnliche Zellen (OBs) und Endothelzellen aus humaner Vena umbilica (HUVECs) in vitro untersucht. Methode: OBs und HUVECs wurden über 14 Tage bei 0,01, 0,1, 1 und 10 µM Zometa® (Zoledronsäure) kultiviert. An 6 Zeitpunkten wurden Stoffwechselaktivität (MTT-Assay) und Proliferationsrate (Cell-Count auf Fotos) ermittelt. Immunhistologische Färbungen zeigte...

  5. Table des illustrations

    OpenAIRE

    2014-01-01

    COULEURS CICERI. Aladin, n° 2 (couverture) CICERI. Aladin, n° 1 CICERI. Ali-Baba, n° 2 ISABEY. Armide, n° 1 LORMIER. La Gipsy, n° 1 LORMIER. La Reine de Chypre, n° 5 LORMIER. La Tarentule, n° 2 CHASSELAT. Guillaume Tell, n° 6 LORMIER. Le Lac des fées, n° 1 CAMBON. Gustave III, n° 3 CICERI. Gustave III, n° 1 CHAPERON. Les Huguenots, n° 17 PERCIER, THIBAULT, FONTAINE. Paul et Virginie, n° 3 CHAPERON. Pierre de Médicis, n° 1 CHAPERON. Le Prophète, n° 18 CAMBON. La Reine de Chypre, n° 4 MÉNAGEO...

  6. La fabrique des extraterrestres

    OpenAIRE

    Poulain, Sébastien

    2012-01-01

    Grâce à différentes stratégies discursives et médiatiques, Radio Ici et Maintenant joue un rôle dans la fabrication de la rumeur de l’existence des extraterrestres. Cette rumeur, teintée de complot, doit servir à légitimer l’utopie messianique et millénariste de cette radio New Age qui dispose de 5 000 auditeurs au quotidien. Cette radio prophétique et thérapeutique participe donc, jusqu’à un certain degré, au renouvellement de l’espace du politico-religieux. Thanks to various media and di...

  7. Liste des auteurs

    OpenAIRE

    2016-01-01

    C. Alba Département de science politique et d’administration, Faculté de droit, Université autonome de Madrid, Espagne. D. Čermák Académie tchèque des sciences, Institut de sociologie, République tchèque. M. Charron Groupe de recherche sur l’innovation municipale Villes Régions Monde, INRS-Urbanisation, Culture et Société, Montréal, Canada. J.-P. Collin Groupe de recherche sur l’innovation municipale Villes Régions Monde, INRS-Urbanisation, Culture et Société, Montréal, Canada. A. Hazan Dire...

  8. Charakterisierung des Burkholderia cenocepacia Aquaglyceroporins

    OpenAIRE

    Wree, Dorothea

    2010-01-01

    In der vorliegenden Arbeit wurde ein Aquaglyceroporin des Krankenhausproblemkeims Burkholderia cenocepacia, BccGlpF, charakterisiert. Unter besonderer Beobachtung stand die Struktur-Funktionsbeziehung der eigentlich kochkonservierten NPA-Motive.

  9. Marais Des Cygnes Wildlife Area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This brochure is for the Marais des Cygnes Wildlife Area, managed by Kansas Department of Wildlife, Parks and Tourism, and located in the floodplain of the Marais...

  10. La recherche des documents (heuristique)

    OpenAIRE

    Langlois, Charles-Victor; Seignobos, Charles

    2014-01-01

    L’histoire se fait avec des documents. Les documents sont les traces qu’ont laissées les pensées et les actes des hommes d’autrefois. Parmi les pensées et les actes des hommes, il en est très peu qui laissent des traces visibles, et ces traces, lorsqu’il s’en produit, sont rarement durables : il suffit d’un accident pour les effacer. Or, toute pensée et tout acte qui n’a pas laissé de traces, directes ou indirectes, ou dont les traces visibles ont disparu, est perdu pour l’histoire : c’est co...

  11. Treatment of contaminated drilling sludge in a bioreactor; Behandlung von Bohrspuelschlaemmen im Bioreaktorverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Noke, A.

    2003-07-01

    Fine-grained contaminated drilling mud from petroleum production processes was purified in an airlift bioreactor. The process regime of bioreactor treatment was optimized, elements of the process periphery were investigated (e.g. purification of reactor off-air in biofilters as well as mud dehydration), and the hazard of the resulting material was assessed.

  12. Evaluation Of Landfill Gas Decay Constant For Municipal Solid Waste Landfills Operated As Bioreactors

    Science.gov (United States)

    Prediction of the rate of gas production from bioreactor landfills is important to optimize energy recovery and to estimate greenhouse gas emissions. Landfill gas (LFG) composition and flow rate were monitored for four years for a conventional and two bioreactor landfill landfil...

  13. Bioconversion of high concentrations of hydrogen sulfide to elemental sulfur in airlift bioreactor.

    Science.gov (United States)

    Zytoon, Mohamed Abdel-Monaem; AlZahrani, Abdulraheem Ahmad; Noweir, Madbuli Hamed; El-Marakby, Fadia Ahmed

    2014-01-01

    Several bioreactor systems are used for biological treatment of hydrogen sulfide. Among these, airlift bioreactors are promising for the bioconversion of hydrogen sulfide into elemental sulfur. The performance of airlift bioreactors is not adequately understood, particularly when directly fed with hydrogen sulfide gas. The objective of this paper is to investigate the performance of an airlift bioreactor fed with high concentrations of H2S with special emphasis on the effect of pH in combination with other factors such as H2S loading rate, oxygen availability, and sulfide accumulation. H2S inlet concentrations between 1,008 ppm and 31,215 ppm were applied and elimination capacities up to 113 g H2S m(-3) h(-1) were achieved in the airlift bioreactor under investigation at a pH range 6.5-8.5. Acidic pH values reduced the elimination capacity. Elemental sulfur recovery up to 95% was achieved under oxygen limited conditions (DO bioreactor tolerated accumulated dissolved sulfide concentrations >500 mg/L at pH values 8.0-8.5, and near 100% removal efficiency was achieved. Overall, the resident microorganisms in the studied airlift bioreactor favored pH values in the alkaline range. The bioreactor performance in terms of elimination capacity and sulfur recovery was better at pH range 8-8.5.

  14. Cultivation of mammalian cells using a single-use pneumatic bioreactor system.

    Science.gov (United States)

    Obom, Kristina M; Cummings, Patrick J; Ciafardoni, Janelle A; Hashimura, Yasunori; Giroux, Daniel

    2014-10-10

    Recent advances in mammalian, insect, and stem cell cultivation and scale-up have created tremendous opportunities for new therapeutics and personalized medicine innovations. However, translating these advances into therapeutic applications will require in vitro systems that allow for robust, flexible, and cost effective bioreactor systems. There are several bioreactor systems currently utilized in research and commercial settings; however, many of these systems are not optimal for establishing, expanding, and monitoring the growth of different cell types. The culture parameters most challenging to control in these systems include, minimizing hydrodynamic shear, preventing nutrient gradient formation, establishing uniform culture medium aeration, preventing microbial contamination, and monitoring and adjusting culture conditions in real-time. Using a pneumatic single-use bioreactor system, we demonstrate the assembly and operation of this novel bioreactor for mammalian cells grown on micro-carriers. This bioreactor system eliminates many of the challenges associated with currently available systems by minimizing hydrodynamic shear and nutrient gradient formation, and allowing for uniform culture medium aeration. Moreover, the bioreactor's software allows for remote real-time monitoring and adjusting of the bioreactor run parameters. This bioreactor system also has tremendous potential for scale-up of adherent and suspension mammalian cells for production of a variety therapeutic proteins, monoclonal antibodies, stem cells, biosimilars, and vaccines.

  15. PERFORMANCE OF NORTH AMERICAN BIOREACTOR LANDFILLS: II. CHEMICAL AND BIOLOGICAL CHARACTERISTICS

    Science.gov (United States)

    The objective of this research was to examine the performance of five North American bioreactor landfills. This paper represents the second of a two part series and addresses biological and chemical aspects of bioreactor performance including gas production and management, and l...

  16. A simple eccentric stirred tank mini-bioreactor: mixing characterization and mammalian cell culture experiments.

    Science.gov (United States)

    Bulnes-Abundis, David; Carrillo-Cocom, Leydi M; Aráiz-Hernández, Diana; García-Ulloa, Alfonso; Granados-Pastor, Marisa; Sánchez-Arreola, Pamela B; Murugappan, Gayathree; Alvarez, Mario M

    2013-04-01

    In industrial practice, stirred tank bioreactors are the most common mammalian cell culture platform. However, research and screening protocols at the laboratory scale (i.e., 5-100 mL) rely primarily on Petri dishes, culture bottles, or Erlenmeyer flasks. There is a clear need for simple-easy to assemble, easy to use, easy to clean-cell culture mini-bioreactors for lab-scale and/or screening applications. Here, we study the mixing performance and culture adequacy of a 30 mL eccentric stirred tank mini-bioreactor. A detailed mixing characterization of the proposed bioreactor is presented. Laser induced fluorescence (LIF) experiments and computational fluid dynamics (CFD) computations are used to identify the operational conditions required for adequate mixing. Mammalian cell culture experiments were conducted with two different cell models. The specific growth rate and the maximum cell density of Chinese hamster ovary (CHO) cell cultures grown in the mini-bioreactor were comparable to those observed for 6-well culture plates, Erlenmeyer flasks, and 1 L fully instrumented bioreactors. Human hematopoietic stem cells were successfully expanded tenfold in suspension conditions using the eccentric mini-bioreactor system. Our results demonstrate good mixing performance and suggest the practicality and adequacy of the proposed mini-bioreactor.

  17. Optimization of denitrifying bioreactor performance with agricultural residue-based filter media

    Science.gov (United States)

    Denitrification bioreactors are a promising technology for mitigation of nitrate-nitrogen (NO3-N) losses in subsurface drainage water. Bioreactors are constructed with carbon substrates, typically wood chips, to provide a substrate for denitrifying microorganisms. Columns were packed with wood chips...

  18. Effects of a perfusion bioreactor activated novel bone substitute in spine fusion in sheep

    DEFF Research Database (Denmark)

    Sørensen, Jesper Roed; Koroma, Kariatta Ester; Ding, Ming;

    2012-01-01

    To evaluate the effect of a large perfusion-bioreactor cell-activated bone substitute, on a two-level large posterolateral spine fusion sheep model.......To evaluate the effect of a large perfusion-bioreactor cell-activated bone substitute, on a two-level large posterolateral spine fusion sheep model....

  19. Biodegradation of toluene using Candida tropicalis immobilized on polymer matrices in fluidized bed bioreactors.

    Science.gov (United States)

    Song, JiHyeon; Namgung, HyeongKyu; Ahmed, Zubair

    2012-11-30

    A yeast strain, Candida tropicalis, was whole-cell-immobilized on polymer matrices of polyethylene glycol (PEG) and polyethylene glycol/activated carbon/alginate (PACA). The polymer matrices were used as fluidized materials in bubble-column bioreactors for the biodegradation of toluene. Simultaneously, another bubble-column bioreactor using granular activated carbon (GAC) and a conventional compost biofilter were operated for comparison. In the compost biofilter, the toluene removal efficiency gradually deteriorated due to the limitation of microbial activity. The toluene removal in the GAC bioreactor was relatively high because of an increase of toluene mass transfer. However, low toluene removal efficiencies were observed in the PEG bioreactor, presumably because the synthetic polymer alone was not suitable for yeast cell immobilization. In the PACA bioreactor, toluene removal was found to be greater than 95% overall. The CO(2) yield coefficient calculated at the highest toluene loading condition for the PACA bioreactor was found to be higher than those observed in the other bioreactors. Furthermore, almost complete elimination capacities were observed in the PACA bioreactor at short-term toluene loading up to 180 g/m(3)/h. In conclusion, the immobilization of C. tropicalis in the PACA matrix resulted in enhanced toluene biodegradation because of the increases of both mass transfer and microbial activity.

  20. Modeling and mitigation of denitrification 'woodchip' bioreactor phosphorus releases during treatment of aquaculture wastewater

    Science.gov (United States)

    Denitrification 'woodchip' bioreactors designed to remove nitrate from agricultural waters may either be phosphorus sources or sinks. A 24 d batch test showed woodchip leaching is an important source of phosphorus during bioreactor start-up with a leaching potential of approximately 20 -30 mg P per ...

  1. Optimizing hydraulic retention times in denitrifying woodchip bioreactors treating recirculating aquaculture system wastewater

    Science.gov (United States)

    The performance of wood-based denitrifying bioreactors to treat high-nitrate wastewaters from aquaculture systems has not previously been demonstrated. Four pilot-scale woodchip bioreactors (approximately 1:10 scale) were constructed and operated for 268 d to determine the optimal range of design hy...

  2. Application of dynamic membranes in anaerobic membranes in anaerobic membrane bioreactor systems

    NARCIS (Netherlands)

    Erşahin, M.E.

    2015-01-01

    Anaerobic membrane bioreactors (AnMBRs) physically ensure biomass retention by the application of a membrane filtration process. With growing application experiences from aerobic membrane bioreactors (MBRs), the combination of membrane and anaerobic processes has received much attention and become m

  3. DESIGNING SULFATE-REDUCING BACTERIA FIELD BIOREACTORS USING THE BEST MODEL

    Science.gov (United States)

    BEST (bioreactor economics, size and time of operation) is a spreadsheet-based model that is used in conjunction with a public domain computer software package, PHREEQCI. BEST is intended to be used in the design process of sulfate-reducing bacteria (SRB)field bioreactors to pas...

  4. Eine erste Analyse des 'Bildungsgutscheins'

    OpenAIRE

    Bruttel, Oliver

    2003-01-01

    Durch die Einführung des Systems des so genannten „Bildungsgutscheins“ hat sich die Leistungserbringung der budgetmäßig wichtigsten Maßnahme der aktiven Arbeitsmarktpolitik seit dem 1. Januar 2003 grundlegend verändert. Wie ist das neue Instrument der Arbeitsmarktpolitik ausgestaltet und wie aus theoretischer und aus praktischer Sicht zu beurteilen? Welche Probleme ergeben sich und welche Alternativen bestehen?

  5. Distribution and mass transfer of dissolved oxygen in a multi-habitat membrane bioreactor.

    Science.gov (United States)

    Tang, Bing; Qiu, Bing; Huang, Shaosong; Yang, Kanghua; Bin, Liying; Fu, Fenglian; Yang, Huiwen

    2015-04-01

    This work investigated the DO distribution and the factors influencing the mass transfer of DO in a multi-habitat membrane bioreactor. Through the continuous measurements of an on-line automatic system, the timely DO values at different zones in the bioreactor were obtained, which gave a detailed description to the distribution of oxygen within the bioreactor. The results indicated that the growth of biomass had an important influence on the distribution of oxygen. As the extension of operational time, the volumetric oxygen mass transfer coefficient (kLa) was generally decreased. With the difference in DO values, a complex environment combining anoxic and oxic state was produced within a single bioreactor, which provided a fundamental guarantee for the total removal of TN. Aeration rate, the concentration and apparent viscosity of MLSS have different influences on kLa, but adjusting the viscosity is a feasible method to improve the mass transfer of oxygen in the bioreactor.

  6. Regulation of mesenchymal stem cell 3D microenvironment: From macro to microfluidic bioreactors.

    Science.gov (United States)

    Sart, Sébastien; Agathos, Spiros N; Li, Yan; Ma, Teng

    2016-01-01

    Human mesenchymal stem cells (hMSCs) have emerged as an important cell type in cell therapy and tissue engineering. In these applications, maintaining the therapeutic properties of hMSCs requires tight control of the culture environments and the structural cell organizations. Bioreactor systems are essential tools to achieve these goals in the clinical-scale expansion and tissue engineering applications. This review summarizes how different bioreactors provide cues to regulate the structure and the chemico-mechanical microenvironment of hMSCs with a focus on 3D organization. In addition to conventional bioreactors, recent advances in microfluidic bioreactors as a novel approach to better control the hMSC microenvironment are also discussed. These advancements highlight the key role of bioreactor systems in preserving hMSC's functional properties by providing dynamic and temporal regulation of in vitro cellular microenvironment.

  7. Propagation and Dissolution of CO2 bubbles in Algae Photo-bioreactors

    Science.gov (United States)

    Kosaraju, Srinivas

    2015-11-01

    Research grade photo-bioreactors are used to study and cultivate different algal species for biofuel production. In an attempt to study the growth properties of a local algal species in rain water, a custom made bioreactor is designed and being tested. Bio-algae consumes dissolved CO2 in water and during its growth cycle, the consumed CO2 must be replenished. Conventional methods use supply of air or CO2 bubbles in the growth medium. The propagation and dissolution of the bubbles, however, are strongly dependent on the design parameters of the photo-bioreactor. In this paper, we discuss the numerical modeling of the air and CO2 bubble propagation and dissolution in the photo-bioreactor. Using the results the bioreactor design will be modified for maximum productivity.

  8. A novel membrane distillation-thermophilic bioreactor system: biological stability and trace organic compound removal.

    Science.gov (United States)

    Wijekoon, Kaushalya C; Hai, Faisal I; Kang, Jinguo; Price, William E; Guo, Wenshan; Ngo, Hao H; Cath, Tzahi Y; Nghiem, Long D

    2014-05-01

    The removal of trace organic compounds (TrOCs) by a novel membrane distillation-thermophilic bioreactor (MDBR) system was examined. Salinity build-up and the thermophilic conditions to some extent adversely impacted the performance of the bioreactor, particularly the removal of total nitrogen and recalcitrant TrOCs. While most TrOCs were well removed by the thermophilic bioreactor, compounds containing electron withdrawing functional groups in their molecular structure were recalcitrant to biological treatment and their removal efficiency by the thermophilic bioreactor was low (0-53%). However, the overall performance of the novel MDBR system with respect to the removal of total organic carbon, total nitrogen, and TrOCs was high and was not significantly affected by the conditions of the bioreactor. All TrOCs investigated here were highly removed (>95%) by the MDBR system. Biodegradation, sludge adsorption, and rejection by MD contribute to the removal of TrOCs by MDBR treatment. PMID:24658107

  9. Production of Calcaride A by Calcarisporium sp. in Shaken Flasks and Stirred Bioreactors.

    Science.gov (United States)

    Tamminen, Anu; Wang, Yanming; Wiebe, Marilyn G

    2015-06-24

    Increased interest in marine resources has led to increased screening of marine fungi for novel bioactive compounds and considerable effort is being invested in discovering these metabolites. For compound discovery, small-scale cultures are adequate, but agitated bioreactors are desirable for larger-scale production. Calcarisporium sp. KF525 has recently been described to produce calcaride A, a cyclic polyester with antibiotic activity, in agitated flasks. Here, we describe improvements in the production of calcaride A in both flasks (13-fold improvement) and stirred bioreactors (200-fold improvement). Production of calcaride A in bioreactors was initially substantially lower than in shaken flasks. The cultivation pH (reduced from 6.8 to bioreactor, which was only slightly less than in shaken flasks (14 mg·g-1, 100 mg·L-1). The results demonstrate that a scalable process for calcaride A production could be developed using an iterative approach with flasks and bioreactors.

  10. Construction and evaluation of urinary bladder bioreactor for urologic tissue-engineering purposes.

    LENUS (Irish Health Repository)

    Davis, Niall F

    2012-01-31

    OBJECTIVE: To design and construct a urinary bladder bioreactor for urologic tissue-engineering purposes and to compare the viability and proliferative activity of cell-seeded extracellular matrix scaffolds cultured in the bioreactor with conventional static growth conditions. MATERIALS AND METHODS: A urinary bladder bioreactor was designed and constructed to replicate physiologic bladder dynamics. The bioreactor mimicked the filling pressures of the human bladder by way of a cyclical low-delivery pressure regulator. In addition, cell growth was evaluated by culturing human urothelial cells (UCs) on porcine extracellular matrix scaffolds in the bioreactor and in static growth conditions for 5 consecutive days. The attachment, viability, and proliferative potential were assessed and compared with quantitative viability indicators and by fluorescent markers for intracellular esterase activity and plasma membrane integrity. Scaffold integrity was characterized with scanning electron microscopy and 4\\

  11. Membrane bioreactors for enzymatic hydrolysis of lactose; Idrolisi enzimatica del lattosio con bioreattori a membrana

    Energy Technology Data Exchange (ETDEWEB)

    Pizzichini, M.; Pilloton, R. [ENEA, Casaccia (Italy). Area Energia e Innovazione; Pontecorvo, M.; Mignogna, G.; Fortunato, A.; Beone, F.

    1993-03-01

    Bioreactor systems obtained by cell or enzyme immobilization offer many advantages compared with native enzyme, intact cell systems or other biocatalysts. Thus, many attempts have been made to design and use new types of bioreactor systems in order to improve performance, enhance productivity and reduce environmental impacts. Membrane bioreactors, obtained by physical immobilization of biocatalysts, in polymeric membrane support, offer such practical advantages as: a continuous separation and transformation process with low product inhibition and suitable hydraulic configuration (backflushing recycling, ultrafiltrating). Specific membrane modules (Amicon VitaFiber), for bioreactor applications are being commercialized. Beta-galctosidase enzyme has successfully been immobilized in a hollow fiber and in ceramic modules to hydrolyze lactose in waste whey. This technical report presents the general properties and performances (permeability, washing procedures, hydraulic configurations, physical and chemical properties) of both, polymeric and ceramic supports, enzyme kinetics, physical and covalent immobilization, mathematical model of the bioreactor and on-line process monitoring.

  12. Chronique des Archives 2010-2011

    OpenAIRE

    Eichenlaub, Jean-Luc

    2012-01-01

    La Chronique des Archives rendant compte des activités 2009 est parue dans la Revue d’Alsace no136, 2010, p. 391‑397. Le lecteur a pu avoir un aperçu des activités des Archives départementales (Bas‑Rhin, Haut‑Rhin, Territoire de Belfort) et des archives municipales de Belfort, Colmar, Erstein, Guebwiller, Illkirch, Illzach, Ingersheim, Mulhouse, Munster, Saint-Louis, Turckheim, Strasbourg. Il n’y a pas eu de Chronique des Archives complète dans la Revue d’Alsace no137, 2011, mais une page con...

  13. Preliminary Study on Airlift Membran-Bioreactor%气升式膜-生物反应器的设计与应用

    Institute of Scientific and Technical Information of China (English)

    徐农; 邢卫红; 徐南平; 时钧

    2002-01-01

    A new type of membrane bioreactor named "airlift membrane-bioreactor" is discussed. For municipal wastewater reclamation, the preliminary study on airlift membrane-bioreactor shows its good performance such as higher flux and lower energy consumption. The airlift membrane-bioreactor is potentially applicable in bioengineering and environmental protection fields.

  14. Des cartographies de connaissances pour un pilotage des ressources humaines et des processus RH

    OpenAIRE

    Sellin, Kelly; Dudezert, Aurélie

    2010-01-01

    La gestion des ressources humaines s'inscrit dans la stratégie des organisations, désireuses de se démarquer d'une concurrence forte et de développer un avantage concurrentiel durable, au travers des connaissances et compétences dont elles disposent. Or, les fonctions RH sont confrontées à une dichotomie court terme/long terme, répondant à la fois aux exigences de l'opérationnel et à une nécessaire gestion anticipée des hommes et de leurs compétences pour répondre aux besoins présents et futu...

  15. Development of thin-film photo-bioreactor and its application to outdoor culture of microalgae.

    Science.gov (United States)

    Yoo, Jae Jun; Choi, Seung Phill; Kim, Jaoon Y H; Chang, Won Seok; Sim, Sang Jun

    2013-06-01

    Photosynthetic microalgae have received much attention as a microbial source of diverse useful biomaterials through CO(2) fixation and various types of photo-bioreactors have been developed for efficient microalgal cultivation. Herein, we developed a novel thin-film photo-bioreactor, which was made of cast polypropylene film, considering outdoor mass cultivation. To develop optimal design of photo-bioreactor, we tested performance of three shapes of thin-film photo-bioreactors (flat, horizontal and vertical tubular shapes) and various parts in the bioreactor. Collectively, vertical tubular bioreactor with H/D ratio 6:1 and cylindrical stainless steel spargers showed the most outstanding performance. Furthermore, the photo-bioreactor was successfully applied to the cultivation of other microalgae such as Chlamydomonas reinhardtii and Chlorella vulgaris. The scalability of photo-bioreactor was confirmed by gradually increasing culture volume from 4 to 25 L and the biomass productivity of each reactor was quite consistent (0.05-0.07 g/L/day) during the cultivation of H. pluvialis under indoor and outdoor conditions. Especially, we also achieved dry cell weight of 4.64 g/L and astaxanthin yield of 218.16 mg/L through long-term cultivation (100 days) under outdoor condition in 15 L photo-bioreactor using Haematococcus pluvialis, which means that the astaxanthin yield from outdoor cultivation is equal or superior to that obtained from controlled indoor condition. Therefore, these results indicate that we can apply this approach to development of optimal photo-bioreactor for the large-scale culture of microalgae and production of useful biomaterials under outdoor condition. PMID:23361185

  16. Development of thin-film photo-bioreactor and its application to outdoor culture of microalgae.

    Science.gov (United States)

    Yoo, Jae Jun; Choi, Seung Phill; Kim, Jaoon Y H; Chang, Won Seok; Sim, Sang Jun

    2013-06-01

    Photosynthetic microalgae have received much attention as a microbial source of diverse useful biomaterials through CO(2) fixation and various types of photo-bioreactors have been developed for efficient microalgal cultivation. Herein, we developed a novel thin-film photo-bioreactor, which was made of cast polypropylene film, considering outdoor mass cultivation. To develop optimal design of photo-bioreactor, we tested performance of three shapes of thin-film photo-bioreactors (flat, horizontal and vertical tubular shapes) and various parts in the bioreactor. Collectively, vertical tubular bioreactor with H/D ratio 6:1 and cylindrical stainless steel spargers showed the most outstanding performance. Furthermore, the photo-bioreactor was successfully applied to the cultivation of other microalgae such as Chlamydomonas reinhardtii and Chlorella vulgaris. The scalability of photo-bioreactor was confirmed by gradually increasing culture volume from 4 to 25 L and the biomass productivity of each reactor was quite consistent (0.05-0.07 g/L/day) during the cultivation of H. pluvialis under indoor and outdoor conditions. Especially, we also achieved dry cell weight of 4.64 g/L and astaxanthin yield of 218.16 mg/L through long-term cultivation (100 days) under outdoor condition in 15 L photo-bioreactor using Haematococcus pluvialis, which means that the astaxanthin yield from outdoor cultivation is equal or superior to that obtained from controlled indoor condition. Therefore, these results indicate that we can apply this approach to development of optimal photo-bioreactor for the large-scale culture of microalgae and production of useful biomaterials under outdoor condition.

  17. Production of biopesticides in an in situ cell retention bioreactor.

    Science.gov (United States)

    Prakash, Gunjan; Srivastava, Ashok K

    2008-12-01

    The seeds of Azadirachta indica contain azadirachtin and other limonoids, which can be used as a biopesticide for crop protection. Significant variability and availability of seed only in arid zones has triggered biotechnological production of biopesticides to cope up with its huge requirement. Batch cultivation of A. indica suspension culture was carried out in statistically optimized media (25.0 g/l glucose, 5.7 g/l nitrate, 0.094 g/l phosphate and 5 g/l inoculum) in 3 l stirred tank bioreactor. This resulted in 15.5 g/l biomass and 0.05 g/l azadirachtin production in 10 days leading to productivity of 5 mg l(-1) day(-1). Possible inhibition by the limiting substrates (C, N, P) were also studied and maximum inhibitory concentrations identified. The batch kinetic/inhibitory data were then used to develop and identify an unstructured mathematical model. The batch model was extrapolated to simulate continuous cultivation with and without cell retention in the bioreactor. Several offline computer simulations were done to identify right nutrient feeding strategies (with respect to key limiting substrates; carbon, nitrate and phosphate) to maintain non-limiting and non-inhibitory substrate concentrations in bioreactor. One such continuous culture (with cell retention) simulation was experimentally implemented. In this cultivation, the cells were propagated batch-wise for 8 days. It was then converted to continuous cultivation by feeding MS salts with glucose (75 g/l), nitrate (10 g/l), and phosphate (0.5 g/l) at a feed rate of 500 ml/day and withdrawing the spent medium at the same rate. The above continuous cultivation (with cell retention) demonstrated an improvement in cell growth to 95.8 g/l and intracellular accumulation of 0.38 g/l azadirachtin in 40 days leading to an overall productivity of 9.5 mg l(-1) day(-1). PMID:18392561

  18. L-Tryptophan depletion bioreactor, a possible cancer therapy

    Directory of Open Access Journals (Sweden)

    Rolf Bambauer

    2015-04-01

    Full Text Available The cancer therapeutic strategies knownto date are not adequate for all cancer patients. Most of them are followed by a high rate of side effects and complications. The L-tryptophan depletion bioreactor is described as a possible new method of cancer therapy. L-tryptophan is an essential amino acid which has been recognized as an important cancer nutrient and its removal can lead to destruction of the tumour. Normal human cells or tumor cells cannot synthesize L-tryptophan and therefore tumor resistance is unlikely to develop. L-tryptophan is also a constituent for different bio-molecules such as Serotonin, Melatonin, and is needed for other synthesis processes in the cell growth. L-tryptophan degrading enzymes with 3 iso-enzymes called tryptophan side chain oxydase (TSO I, II, III were isolated. The 3 iso-enzymes can be differentiated by tryptic digestion. They have different molecular weights with different effectivenesses. All the TSO enzymes have heme that can catalyze essentially similar reactions involving L-tryptophan as a substrate. The most effective TSO is the type TSO III. A column which contained TSO as a bioreactor was integrated in a plasmapheresis unit and tested it in different animals. In sheep and rabbits L-tryptophan depletion in plasma was shown at 95% and 100% rates respectively by a single pass through the bioreactor. The results in immune supprimized rats with tumors were impressive, too. In 20 different tumor cell lines there were different efficacies. Brest cancer and medulloblastoma showed the greatest efficacy of L-tryptophan degrading. The gene technology of TSO production from Pseudomonas is associated with formation of endotoxins. This disadvantage can be prevented by different washing procedures or by using fungal sources for the TSO production. TSO III is developed to treat cancer diseases successfully, and has low side effects. A combination of L-tryptophan depletion with all available cancer therapies is

  19. Cell Cycle Progression of Human Cells Cultured in Rotating Bioreactor

    Science.gov (United States)

    Parks, Kelsey

    2009-01-01

    Space flight has been shown to alter the astronauts immune systems. Because immune performance is complex and reflects the influence of multiple organ systems within the host, scientists sought to understand the potential impact of microgravity alone on the cellular mechanisms critical to immunity. Lymphocytes and their differentiated immature form, lymphoblasts, play an important and integral role in the body's defense system. T cells, one of the three major types of lymphocytes, play a central role in cell-mediated immunity. They can be distinguished from other lymphocyte types, such as B cells and natural killer cells by the presence of a special receptor on their cell surface called T cell receptors. Reported studies have shown that spaceflight can affect the expression of cell surface markers. Cell surface markers play an important role in the ability of cells to interact and to pass signals between different cells of the same phenotype and cells of different phenotypes. Recent evidence suggests that cell-cycle regulators are essential for T-cell function. To trigger an effective immune response, lymphocytes must proliferate. The objective of this project is to investigate the changes in growth of human cells cultured in rotating bioreactors and to measure the growth rate and the cell cycle distribution for different human cell types. Human lymphocytes and lymphoblasts will be cultured in a bioreactor to simulate aspects of microgravity. The bioreactor is a cylindrical culture vessel that incorporates the aspects of clinostatic rotation of a solid fluid body around a horizontal axis at a constant speed, and compensates gravity by rotation and places cells within the fluid body into a sustained free-fall. Cell cycle progression and cell proliferation of the lymphocytes will be measured for a number of days. In addition, RNA from the cells will be isolated for expression of genes related in cell cycle regulations.

  20. Trace Gas Emission from in-Situ Denitrifying Bioreactors

    Science.gov (United States)

    Pluer, W.; Walter, M. T.; Geohring, L.

    2014-12-01

    Despite decades of concerted effort to mitigate nonpoint source nitrate (NO3-) pollution from agricultural lands, these efforts have not been sufficient to arrest eutrophication. A primary process for removing excess NO3- from water is denitrification, where denitrifying bacteria use NO3- for respiration in the absence of oxygen. Denitrification results in reduced forms of nitrogen, often dinitrogen gas (N2) but also nitrous oxide (N2O), an aggressive greenhouse gas. A promising solution to NO3- pollution is to intercept agricultural discharges with denitrifying bioreactors (DNBRs). DNBRs provide conditions ideal for denitrifiers: an anaerobic environment, sufficient organic matter, and excess NO3-. These conditions are also ideal for methanogens, which produce methane (CH4), another harmful trace gas. While initial results from bioreactor studies show that they can cost-effectively remove NO3-, trace gas emissions are an unintended consequence. This study's goal was to determine how bioreactor design promotes denitrification while limiting trace gas production. Reactor inflow and outflow water samples were tested for nutrients, including NO3-, and dissolved inflow and outflow gas samples were tested for N2O and CH4. NO3- reduction and trace gas production were evaluated at various residence times, pHs, and inflow NO3- concentrations in field and lab-scale reactors. Low NO3- reduction indicated conditions that stressed denitrifying bacteria while high reductions indicated designs that optimized pollutant treatment for water quality. Several factors influenced high N2O, suggesting non-ideal conditions for the final step of complete denitrification. High CH4 emissions pointed to reactor media choice for discouraging methanogens, which may remove competition with denitrifiers. It is critical to understand all of potential impacts that DNBRs may have, which means identifying processes and design specifications that may affect them.

  1. Production of succinic acid in basket and mobile bed bioreactors-Comparative analysis of substrate mass transfer aspects☆

    Institute of Scientific and Technical Information of China (English)

    Anca-Irina Galaction; Dan Cacaval; Ramona-Mihaela Matran; Alexandra Tucaliuc

    2016-01-01

    The glucose mass transfer in the biosynthesis of succinic acid with immobilized Actinobacil us succinogenes cel s has been comparatively analyzed for a bioreactor with mobile bed vs. a stationary basket bioreactor. The process has been considered to occur under substrate and product inhibitory effects. The results indicated that the biore-actor with mobile bed is more efficient for biocatalyst particles with a diameter over 3 mm, while the basket bio-reactor is more efficient for smal er biocatalyst particles and basket bed thickness below 5 mm. The performances of both configurations of immobilized A. succinogenes cell beds were found to be superior to the column packed bed bioreactor.

  2. Mixing and In situ product removal in micro-bioreactors

    OpenAIRE

    Li, X

    2009-01-01

    Summary Of the thesis :’ Mixing and In-situ product removal in micro bioreactors’ by Xiaonan Li The work presented in this thesis is a part of a large cluster project, which was formed between DSM, Organon, Applikon and two university groups (TU Delft and University of Twente), under the ACTS and IBOS program. The aim of this cluster project was to develop a system consisting of parallel bioreactors of 30 to 200 microliter working volume for the cultivation of micro-organisms under well contr...

  3. Transgenic rice endosperm as a bioreactor for molecular pharming.

    Science.gov (United States)

    Ou, Jiquan; Guo, Zhibin; Shi, Jingni; Wang, Xianghong; Liu, Jingru; Shi, Bo; Guo, Fengli; Zhang, Chufu; Yang, Daichnag

    2014-04-01

    Plants provide a promising expression platform for producing recombinant proteins with several advantages in terms of high expression level, lower production cost, scalability, and safety and environment-friendly. Molecular pharming has been recognized as an emerging industry with strategic importance that could play an important role in economic development and healthcare in China. Here, this review represents the significant advances using transgenic rice endosperm as bioreactor to produce various therapeutic recombinant proteins in transgenic rice endosperm and large-scale production of OsrHSA, and discusses the challenges to develop molecular pharming as an emerging industry with strategic importance in China. PMID:24413763

  4. Transgenic rice endosperm as a bioreactor for molecular pharming.

    Science.gov (United States)

    Ou, Jiquan; Guo, Zhibin; Shi, Jingni; Wang, Xianghong; Liu, Jingru; Shi, Bo; Guo, Fengli; Zhang, Chufu; Yang, Daichnag

    2014-04-01

    Plants provide a promising expression platform for producing recombinant proteins with several advantages in terms of high expression level, lower production cost, scalability, and safety and environment-friendly. Molecular pharming has been recognized as an emerging industry with strategic importance that could play an important role in economic development and healthcare in China. Here, this review represents the significant advances using transgenic rice endosperm as bioreactor to produce various therapeutic recombinant proteins in transgenic rice endosperm and large-scale production of OsrHSA, and discusses the challenges to develop molecular pharming as an emerging industry with strategic importance in China.

  5. Anaerobic electrochemical membrane bioreactor and process for wastewater treatment

    KAUST Repository

    Amy, Gary

    2015-07-09

    An anaerobic electrochemical membrane bioreactor (AnEMBR) can include a vessel into which wastewater can be introduced, an anode electrode in the vessel suitable for supporting electrochemically active microorganisms (EAB, also can be referred to as anode reducing bacteria, exoelectrogens, or electricigens) that oxidize organic compounds in the wastewater, and a cathode membrane electrode in the vessel, which is configured to pass a treated liquid through the membrane while retaining the electrochemically active microorganisms and the hydrogenotrophic methanogens (for example, the key functional microbial communities, including EAB, methanogens and possible synergistic fermenters) in the vessel. The cathode membrane electrode can be suitable for catalyzing the hydrogen evolution reaction to generate hydro en.

  6. Orbitally Shaken Bioreactors - Viscosity effects on flow characteristics

    OpenAIRE

    Ducci, A.; Weheliye, W. H.

    2014-01-01

    Phase resolved PIV measurements were carried out to assess the flow dynamics occurring in orbitally shaken bioreactors of cylindrical geometry when working fluids of increasing viscosity are considered. Study of the phase-resolved flow characteristics allowed to built a Re-Fr map, where four quadrants associated to di fferent flow regimes are identifi ed: in-phase toroidal vortex (low Fr, high Re), out-of-phase precessional vortex (high Fr, high Re), in-phase single vortex (low Fr, low Re), o...

  7. Enrichment of carbon monoxide utilising microorganisms from methanogenic bioreactor sludge

    OpenAIRE

    Pereira, Ana Luísa; Stams, A.J.M.; Alves, M. M.; Sousa, D.Z.

    2015-01-01

    Conversion of CO is the rate limiting step during anaerobic conversion of syngas (a gaseous mixture mainly composed of CO, CO2 and H2). In this work we study the microbial diversity in anaerobic sludge submitted to extended contact to syngas in a multi-orifice baffled bioreactor (MOBB). Methane was the main product resulting from syngas conversion in the MOBB. Enrichment cultures started with this sludge produced methane as final product, but also acetate. 16S rRNA gene analysis revealed a pr...

  8. Effect of Mixing on Microorganism Growth in Loop Bioreactors

    Directory of Open Access Journals (Sweden)

    A. M. Al Taweel

    2012-01-01

    Full Text Available The impact of mixing on the promotion of microorganism growth rate has been analyzed using a multiphase forced-circulation pipe-loop reactor model capable of identifying conditions under which it is possible to convert natural gas into Single-Cell Protein. The impact of mixing in the interphase mass transfer was found to exert a critical role in determining the overall productivity of the bioreactor, particularly at the high cell loadings needed to reduce the capital costs associated with the large-scale production needed for the production of relatively low-value SCP in a sustainable manner.

  9. Transient Behavior of Ethanol Fermentation in Immobilized Cell Bioreactors*

    OpenAIRE

    Tohru, KANNO; Yoshinori, FUJISHIGE; Hiroyuki, Ito; koichi, yamazaki; Masayoshi, KOBAYASHI

    1990-01-01

    The dynamic behavior of ethanol fermentation catalysed by an immobilized cell has been studied in batch and continuous stirred tank bioreactors, changing the operating conditions in a stepwise fashion. The rate of ethanol fermentation in the flow reactor reaches a new steady state within 60 min for the stepwise change in temperature or flow rate at 15〜30℃ and the residence time t_R=40 hr. The rate of fermentation obeys the Lineweaven-Burk plot and the Michaelis constant is calculated

  10. CCC/WPA study : Des Lacs NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Summary of the Civilian Conservation Corps (CCC) camp at Des Lacs National Wildlife Refuge from July 1935-May 1942 to carry on restoration and development of Des...

  11. Gestion des connaissances des firmes globales : entre pratiques de codification et pratiques de diffusion

    OpenAIRE

    Paraponaris, Claude; Simoni, Gilda

    2004-01-01

    Le management des connaissances suscite beaucoup d'interrogations au sujet des méthodes mises en œuvre. Cet article propose une étude des pratiques de management des connaissances au sein de firmes multinationales. Deux résultats principaux sont dégagés. Nous montrons d'une part que plusieurs méthodes assez différentes du point de vue des objectifs et des usages peuvent être articulées au sein d'une même entreprise. Nous proposons également une typologie de pratiques de gestion des connaissan...

  12. La théorie des industries culturelles (et informationnelles, composante des SIC

    Directory of Open Access Journals (Sweden)

    Bernard Miège

    2012-09-01

    Full Text Available Inaugurer le Cahier central de la Revue des SIC est certes une forme de reconnaissance, mais cela comporte des obligations, au premier rang desquelles la nécessité d’intéresser des lecteurs a priori pas immédiatement concernés par la thématique.Si la théorie des industries culturelles est devenue progressivement une approche marquante des SIC, en France, en Europe et plus largement encore (avec des dénominations variables et des modalités spécifiques, ce n’est en effet ni en le proclamant ha...

  13. Peste des petits ruminants.

    Science.gov (United States)

    Parida, S; Muniraju, M; Mahapatra, M; Muthuchelvan, D; Buczkowski, H; Banyard, A C

    2015-12-14

    Peste des petits ruminants virus causes a highly infectious disease of small ruminants that is endemic across Africa, the Middle East and large regions of Asia. The virus is considered to be a major obstacle to the development of sustainable agriculture across the developing world and has recently been targeted by the World Organisation for Animal Health (OIE) and the Food and Agriculture Organisation (FAO) for eradication with the aim of global elimination of the disease by 2030. Fundamentally, the vaccines required to successfully achieve this goal are currently available, but the availability of novel vaccine preparations to also fulfill the requisite for differentiation between infected and vaccinated animals (DIVA) may reduce the time taken and the financial costs of serological surveillance in the later stages of any eradication campaign. Here, we overview what is currently known about the virus, with reference to its origin, updated global circulation, molecular evolution, diagnostic tools and vaccines currently available to combat the disease. Further, we comment on recent developments in our knowledge of various recombinant vaccines and on the potential for the development of novel multivalent vaccines for small ruminants. PMID:26443889

  14. Terre des hommes

    CERN Document Server

    Staff Association

    2012-01-01

    Transformez votre téléphone portable en geste de solidarité ! Collecte du 12 au 23 novembre 2012   Faites un geste simple et utile en déposant vos téléphones portables inutilisés dans les urnes installées dans les trois restaurants du CERN. En Suisse, une personne change tous les 12 à 18 mois de téléphone portable. La plupart de nos vieux appareils sont simplement laissés à l’abandon avec comme seule fonction de parer une éventuelle panne à venir. On  estime ainsi que 8 millions de portables sont inutilisés, alors qu'entre 30 et 50% peuvent être réutilisés. L'action Solidarcomm leur offre une deuxième vie ! Terre des Hommes Suisse, dans le cadre de la campagne Solidarcomm, collecte et valorise vos téléphones inutilis&...

  15. Exploration et gestion des connaissances des ressources en IHM

    OpenAIRE

    André, Fabien; Artignan, Guillaume; Cordeil, Maxime; Hoarau, Raphaël; Vo, Dong-Bach

    2010-01-01

    Nous présentons dans l' article le résultat d'un travail réalisé à l'école de Printemps 2010 de l'AFIHM. L'analyse des activités liées à la réalisation d' un état de l'art nous montre qu'une des tâches les plus compliquées est la familiarisation avec un nouveau domaine. Pour outiller cette activité, nous présentons des pistes de réflexion basées sur une analogie avec la mémoire humaine.

  16. La mousson, pluie des agriculteurs et vent des marins

    OpenAIRE

    Aubaile-Sallenave, Françoise

    2014-01-01

    La mousson, c’est un mot arabe ayant une origine et une histoire propre. Ce sont aussi des vents et des courants marins qui vont de l’océan Indien aux mers de Chine et du Japon. C’est une zone de mouvements intenses mettant en contact des populations très diverses.La mousson a facilité depuis fort longtemps les voyages est - ouest (Chine vers Asie du sud-est et Inde) et ouest-est (Arabie vers Inde, Asie du sud-est et Chine), voyages qui donnent accès aux îles et presqu’îles de l’Asie du sud-e...

  17. Current algebra; Algebre des courants

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    The first three chapters of these lecture notes are devoted to generalities concerning current algebra. The weak currents are defined, and their main properties given (V-A hypothesis, conserved vector current, selection rules, partially conserved axial current,...). The SU (3) x SU (3) algebra of Gell-Mann is introduced, and the general properties of the non-leptonic weak Hamiltonian are discussed. Chapters 4 to 9 are devoted to some important applications of the algebra. First one proves the Adler- Weisberger formula, in two different ways, by either the infinite momentum frame, or the near-by singularities method. In the others chapters, the latter method is the only one used. The following topics are successively dealt with: semi leptonic decays of K mesons and hyperons, Kroll- Ruderman theorem, non leptonic decays of K mesons and hyperons ( {delta}I = 1/2 rule), low energy theorems concerning processes with emission (or absorption) of a pion or a photon, super-convergence sum rules, and finally, neutrino reactions. (author) [French] La premiere partie de ce cours (trois premiers chapitres), traite des generalites concernant l'algebre de courants. Apres une definition rapide des courants faibles et un rappel de leurs proprietes (hypothese V-A, conservation du courant vecteur, regles de selection, courant axial partiellement conserve,...), l'on introduit l'algebre de Gell-Mann SU (3) x SU (3), et discute les proprietes generales de l'Hamiltonien faible non leptonique. Les chapitres IV a IX sont consacres a des applications importantes de l'algebre des courants. En premier lieu l'on demontre la formule de Adler et Weisberger, par deux methodes differentes, celle dite du repere de moment infini et celle des singularites proches. Cette derniere est seule utilisee dans la suite. Puis, l'on traite successivement les problemes suivants: desintegrations semi-leptoniques des mesons K et des hyperons, theoreme de Kroll

  18. Biotechnologie des archées

    OpenAIRE

    Querellou, Joel

    2010-01-01

    La majorité des enzymes utilisées dans l’industrie provient des bactéries et des levures. Mais les conditions extrêmes dans lesquelles se développent de nombreuses espèces d’archées font que leurs constituants cellulaires possèdent des propriétés et une stabilité propices à leur utilisation en biotechnologie.

  19. Design and Performance of an Automated Bioreactor for Cell Culture Experiments in a Microgravity Environment

    Science.gov (United States)

    Kim, Youn-Kyu; Park, Seul-Hyun; Lee, Joo-Hee; Choi, Gi-Hyuk

    2015-03-01

    In this paper, we describe the development of a bioreactor for a cell-culture experiment on the International Space Station (ISS). The bioreactor is an experimental device for culturing mouse muscle cells in a microgravity environment. The purpose of the experiment was to assess the impact of microgravity on the muscles to address the possibility of longterm human residence in space. After investigation of previously developed bioreactors, and analysis of the requirements for microgravity cell culture experiments, a bioreactor design is herein proposed that is able to automatically culture 32 samples simultaneously. This reactor design is capable of automatic control of temperature, humidity, and culture-medium injection rate; and satisfies the interface requirements of the ISS. Since bioreactors are vulnerable to cell contamination, the medium-circulation modules were designed to be a completely replaceable, in order to reuse the bioreactor after each experiment. The bioreactor control system is designed to circulate culture media to 32 culture chambers at a maximum speed of 1 ml/min, to maintain the temperature of the reactor at 36°C, and to keep the relative humidity of the reactor above 70%. Because bubbles in the culture media negatively affect cell culture, a de-bubbler unit was provided to eliminate such bubbles. A working model of the reactor was built according to the new design, to verify its performance, and was used to perform a cell culture experiment that confirmed the feasibility of this device.

  20. Thinking beyond the Bioreactor Box: Incorporating Stream Ecology into Edge-of-Field Nitrate Management.

    Science.gov (United States)

    Goeller, Brandon C; Febria, Catherine M; Harding, Jon S; McIntosh, Angus R

    2016-05-01

    Around the world, artificially drained agricultural lands are significant sources of reactive nitrogen to stream ecosystems, creating substantial stream health problems. One management strategy is the deployment of denitrification enhancement tools. Here, we evaluate the factors affecting the potential of denitrifying bioreactors to improve stream health and ecosystem services. The performance of bioreactors and the structure and functioning of stream biotic communities are linked by environmental parameters like dissolved oxygen and nitrate-nitrogen concentrations, dissolved organic carbon availability, flow and temperature regimes, and fine sediment accumulations. However, evidence of bioreactors' ability to improve waterway health and ecosystem services is lacking. To improve the potential of bioreactors to enhance desirable stream ecosystem functioning, future assessments of field-scale bioreactors should evaluate the influences of bioreactor performance on ecological indicators such as primary production, organic matter processing, stream metabolism, and invertebrate and fish assemblage structure and function. These stream health impact assessments should be conducted at ecologically relevant spatial and temporal scales. Bioreactors have great potential to make significant contributions to improving water quality, stream health, and ecosystem services if they are tailored to site-specific conditions and implemented strategically with land-based and stream-based mitigation tools within watersheds. This will involve combining economic, logistical, and ecological information in their implementation. PMID:27136152

  1. [Research on ursolic acid production of Eriobotrya japonica cell suspension culture in WAVE bioreactor].

    Science.gov (United States)

    Li, Hui-hua; Yao, De-heng; Xu, Jian; Wang, Wei; Chang, Qiang; Su, Ming-hua

    2015-05-01

    Through scale-up cultivation of Eriobotrya japonica suspension cells using WAVE bioreactor, the cell growth and ursolic acid (UA) accumulation were studied. The comparison test was carried out in the flask and the reactor with cell dry weight (DW) and UA content as evaluation indexes. The culture medium, DW and UA content were compared in 1 L and 5 L working volumes of bioreactor. The orthogonal test with main actors of inoculation amount, speed and angle of rotation was developed to find the optimal combination, in 1 L working volume of bioreactor. DW of the cell growth and the UA content in bioreactor were higher than those of the shaker by 105.5% and 27.65% respectively. In bioreactor, the dynamic changes of elements in the fluid culture, the dry weight of the cell growth and the UA content in 1 L and 5 L working volumes were similar. Inoculation of 80 g, rotational speed of 26 r · min(-1), and angle of 6 ° was the optimal combination, and the cell biomass of 19.01 g · L(-1) and the UA content of 27.750 mg · g(-1) were achieved after 100 h cultivation in 1 L working volume of bioreactor. WAVE Bioreactor is more suitable than flasks for the E. japonica cell suspension culture, and culture parameters can be achieved from 1 L to 5 L amplification.

  2. Thinking beyond the Bioreactor Box: Incorporating Stream Ecology into Edge-of-Field Nitrate Management.

    Science.gov (United States)

    Goeller, Brandon C; Febria, Catherine M; Harding, Jon S; McIntosh, Angus R

    2016-05-01

    Around the world, artificially drained agricultural lands are significant sources of reactive nitrogen to stream ecosystems, creating substantial stream health problems. One management strategy is the deployment of denitrification enhancement tools. Here, we evaluate the factors affecting the potential of denitrifying bioreactors to improve stream health and ecosystem services. The performance of bioreactors and the structure and functioning of stream biotic communities are linked by environmental parameters like dissolved oxygen and nitrate-nitrogen concentrations, dissolved organic carbon availability, flow and temperature regimes, and fine sediment accumulations. However, evidence of bioreactors' ability to improve waterway health and ecosystem services is lacking. To improve the potential of bioreactors to enhance desirable stream ecosystem functioning, future assessments of field-scale bioreactors should evaluate the influences of bioreactor performance on ecological indicators such as primary production, organic matter processing, stream metabolism, and invertebrate and fish assemblage structure and function. These stream health impact assessments should be conducted at ecologically relevant spatial and temporal scales. Bioreactors have great potential to make significant contributions to improving water quality, stream health, and ecosystem services if they are tailored to site-specific conditions and implemented strategically with land-based and stream-based mitigation tools within watersheds. This will involve combining economic, logistical, and ecological information in their implementation.

  3. Microbial acetate oxidation in horizontal rotating tubular bioreactor

    Indian Academy of Sciences (India)

    A Slavica; B Šantek; S Novak; V Marić

    2004-06-01

    The aim of this work was to investigate the possibility of conducting a continuous aerobic bioprocess in a horizontal rotating tubular bioreactor (HRTB). Aerobic oxidation of acetate by the action of a mixed microbial culture was chosen as a model process. The microbial culture was not only grown in a suspension but also in the form of a biofilm on the interior surface of HRTB. Efficiency of the bioprocess was monitored by determination of the acetate concentration and chemical oxygen demand (COD). While acetate inlet concentration and feeding rate influenced efficiency of acetate oxidation, the bioreactor rotation speed did not influence the bioprocess dynamics significantly. Gradients of acetate concentration and pH along HRTB were more pronounced at lower feeding rates. Volumetric load of acetate was proved to be the most significant parameter. High volumetric loads (above 2 g acetate l–1 h–1) gave poor acetate oxidation efficiency (only 17 to 50%). When the volumetric load was in the range of 0.60–1.75 g acetate l–1 h–1, acetate oxidation efficiency was 50–75%. At lower volumetric loads (0.14–0.58 g acetate l–1 h–1), complete acetate consumption was achieved. On the basis of the obtained results, it can be concluded that HRTB is suitable for conducting aerobic continuous bioprocesses.

  4. Submerged anaerobic membrane bioreactor for wastewater treatment and energy generation.

    Science.gov (United States)

    Bornare, J B; Adhyapak, U S; Minde, G P; Kalyan Raman, V; Sapkal, V S; Sapkal, R S

    2015-01-01

    Compared with conventional wastewater treatment processes, membrane bioreactors (MBRs) offer several advantages including high biodegradation efficiency, excellent effluent quality and smaller footprint. However, it has some limitations on account of its energy intensive operation. In recent years, there has been growing interest in use of anaerobic membrane bioreactors (AnMBRs) due to their potential advantages over aerobic systems, which include low sludge production and energy generation in terms of biogas. The aim of this study was to evaluate the performance of a submerged AnMBR for the treatment of synthetic wastewater having 4,759 mg/l chemical oxygen demand (COD). The COD removal efficiency was over 95% during the performance evaluation study. Treated effluent with COD concentration of 231 mg/l was obtained for 25.5 hours hydraulic retention time. The obtained total organic carbon concentrations in feed and permeate were 1,812 mg/l and 89 mg/l, respectively. An average biogas generation and yield were 25.77 l/d and 0.36 m3/kg COD, respectively. Evolution of trans-membrane pressure (TMP) as a function of time was studied and an average TMP of 15 kPa was found suitable to achieve membrane flux of 12.17 l/(m2h). Almost weekly back-flow chemical cleaning of the membrane was found necessary to control TMP within the permissible limit of 20 kPa. PMID:26038930

  5. Comparison between controlled landfill reactor and conditioned landfill bioreactor

    Institute of Scientific and Technical Information of China (English)

    LUO Feng; CHEN Wan-zhi; SONG Fu-zhong; LI Xiao-peng; ZHANG Guo-qing

    2004-01-01

    Bioreactor landfills allow a more active landfill management that recognizes the biological, chemical and physical processes involved in a landfill environment. The results of laboratory-scale simulators of landfill reactors treating municipal solid wastes were studied, the effect of solid waste size, leachate recirculation, nutrient balance, pH value, moisture content and temperature on the rate of municipal solid waste(MSW) biodegradation were determined, and it indicated the optimum pH value, moisture content and temperature can used to decompose MSW. The results of waste biodegradation were compared with that of the simulators of the leachate-recirculated landfill and conservative sanitary landfill. In the control experiment the antitheses of a decreasing trend of the organic load, measured as biological oxygen demand and chemical oxygen demand, was shown, and heavy metals concentration was observed. An obvious enhancement of effective disposal from simulator of conservative sanitary landfill(CSL), to that of leachate-recirculated landfill(LRL) and to that of conditioned bioreactor landfill(CBL) would be noted, through displaying the compared results of solid waste settlement, heavy metal concentration in leachate, methane production rate, biogas composition, BOD and COD as well as their ratio.

  6. Pulse shear stress for anaerobic membrane bioreactor fouling control.

    Science.gov (United States)

    Yang, Jixiang; Spanjers, Henri; van Lier, Jules B

    2011-01-01

    Increase of shear stress at membrane surfaces is a generally applied strategy to minimize membrane fouling. It has been reported that a two-phase flow, better known as slug flow, is an effective way to increase shear stress. Hence, slug flow was introduced into an anaerobic membrane bioreactor for membrane fouling control. Anaerobic suspended sludge was cultured in an anaerobic membrane bioreactor (AMBR) operated with a side stream inside-out tubular membrane unit applying sustainable flux flow regimes. The averaged particle diameter decreased from 20 to 5 microm during operation of the AMBR. However, the COD removal efficiency did not show any significant deterioration, whereas the specific methanogenic activity (SMA) increased from 0.16 to 0.41 gCOD/g VSS/day. Nevertheless, the imposed gas slug appeared to be insufficient for adequate fouling control, resulting in rapidly increasing trans membrane pressures (TMP) operating at a flux exceeding 16 L/m2/h. Addition of powdered activated carbon (PAC) enhanced the effect of slug flow on membrane fouling. However, the combined effect was still considered as not being significant. The tubular membrane was subsequently equipped with inert inserts for creating a locally increased shear stress for enhanced fouling control. Results show an increase in the membrane flux from 16 L/m2/h to 34 L/m2/h after the inserts were mounted in the membrane tube. PMID:22097007

  7. Osmotic membrane bioreactor for phenol biodegradation under continuous operation.

    Science.gov (United States)

    Praveen, Prashant; Loh, Kai-Chee

    2016-03-15

    Continuous phenol biodegradation was accomplished in a two-phase partitioning osmotic membrane bioreactor (TPPOMBR) system, using extractant impregnated membranes (EIM) as the partitioning phase. The EIMs alleviated substrate inhibition during prolonged operation at influent phenol concentrations of 600-2000mg/L, and also at spiked concentrations of 2500mg/L phenol restricted to 2 days. Filtration of the effluent through forward osmosis maintained high biomass concentration in the bioreactor and improved effluent quality. Steady state was reached in 5-6 days at removal rates varying between 2000 and 5500mg/L-day under various conditions. Due to biofouling and salt accumulation, the permeate flux varied from 1.2-7.2 LMH during 54 days of operation, while maintaining an average hydraulic retention time of 7.4h. A washing cycle, comprising 1h osmotic backwashing using 0.5M NaCl and 2h washing with water, facilitated biofilm removal from the membranes. Characterization of the extracellular polymeric substances (EPS) through FTIR showed peaks between 1700 and 1500cm(-1), 1450-1450cm(-1) and 1200-1000cm(-1), indicating the presence of proteins, phenols and polysaccharides, respectively. The carbohydrate to protein ratio in the EPS was estimated to be 0.3. These results indicate that TPPOMBR can be promising in continuous treatment of phenolic wastewater.

  8. Glyco-engineering for biopharmaceutical production in moss bioreactors

    Directory of Open Access Journals (Sweden)

    Eva L. Decker

    2014-07-01

    Full Text Available The production of recombinant biopharmaceuticals (pharmaceutical proteins is a strongly growing area in the pharmaceutical industry. While most products to date are produced in mammalian cell cultures, namely CHO cells, plant-based production systems gained increasing acceptance over the last years. Different plant systems have been established which are suitable for standardization and precise control of cultivation conditions, thus meeting the criteria for pharmaceutical production.The majority of biopharmaceuticals comprise glycoproteins. Therefore, differences in protein glycosylation between humans and plants have to be taken into account and plant-specific glycosylation has to be eliminated to avoid adverse effects on quality, safety and efficacy of the products.The basal land plant Physcomitrella patens (moss has been employed for the recombinant production of high-value therapeutic target proteins (e.g., Vascular Endothelial Growth Factor, Complement Factor H, monoclonal antibodies, Erythropoietin. Being genetically excellently characterized and exceptionally amenable for precise gene targeting via homologous recombination, essential steps for the optimization of moss as a bioreactor for the production of recombinant proteins have been undertaken.Here, we discuss the glyco-engineering approaches to avoid non-human N- and O-glycosylation on target proteins produced in moss bioreactors.

  9. Modeling of leachate recirculation using vertical wells in bioreactor landfills.

    Science.gov (United States)

    Feng, Shi-Jin; Cao, Ben-Yi; Zhang, Xu; Xie, Hai-Jian

    2015-06-01

    Leachate recirculation (LR) in municipal solid waste (MSW) landfills operated as bioreactors offers significant economic and environmental benefits. The subsurface application method of vertical wells is one of the most common LR techniques. The objective of this study was to develop a novel two-dimensional model of leachate recirculation using vertical wells. This novel method can describe leachate flow considering the effects of MSW settlement while also accounting separately for leachate flow in saturated and unsaturated zones. In this paper, a settlement model for MSW when considering the effects of compression and biodegradation on the MSW porosity was adopted. A numerical model was proposed using new governing equations for the saturated and unsaturated zones of a landfill. The following design parameters were evaluated by simulating the recirculated leachate volume and the influence zones of waste under steady-state flow conditions: (1) the effect of MSW settlement, (2) the effect of the initial void ratio, (3) the effect of the injected head, (4) the effect of the unit weight, (5) the effect of the biodegradation rate, and (6) the effect of the compression coefficient. The influence zones of LR when considering the effect of MSW settlement are smaller than those when neglecting the effect. The influence zones and LR volume increased with an increase in the injection pressure head and initial void ratio of MSW. The proposed method and the calculation results can provide important insight into the hydrological behavior of bioreactor landfills. PMID:25874416

  10. Thiosulphate conversion in a methane and acetate fed membrane bioreactor.

    Science.gov (United States)

    Suarez-Zuluaga, Diego A; Timmers, Peer H A; Plugge, Caroline M; Stams, Alfons J M; Buisman, Cees J N; Weijma, Jan

    2016-02-01

    The use of methane and acetate as electron donors for biological reduction of thiosulphate in a 5-L laboratory membrane bioreactor was studied and compared to disproportionation of thiosulphate as competing biological reaction. The reactor was operated for 454 days in semi-batch mode; 30 % of its liquid phase was removed and periodically replenished (days 77, 119, 166, 258, 312 and 385). Although the reactor was operated under conditions favourable to promote thiosulphate reduction coupled to methane oxidation, thiosulphate disproportionation was the dominant microbial process. Pyrosequencing analysis showed that the most abundant microorganisms in the bioreactor were phototrophic green sulphur bacteria (GSB) belonging to the family Chlorobiaceae and thiosulphate-disproportionating bacteria belonging to the genus Desulfocapsa. Even though the reactor system was surrounded with opaque plastic capable of filtering most of the light, the GSB used it to oxidize the hydrogen sulphide produced from thiosulphate disproportionation to elemental sulphur. Interrupting methane and acetate supply did not have any effect on the microbial processes taking place. The ultimate goal of our research was to develop a process that could be applied for thiosulphate and sulphate removal and biogenic sulphide formation for metal precipitation. Even though the system achieved in this study did not accomplish the targeted conversion using methane as electron donor, it does perform microbial conversions which allow to directly obtain elemental sulphur from thiosulphate.

  11. Characterization of Microbial Communities Found in Bioreactor Effluent

    Science.gov (United States)

    Flowe, Candice

    2013-01-01

    The purpose of this investigation was to examine microbial communities of simulated wastewater effluent from hollow fiber membrane bioreactors collected from the Space Life Science Laboratory and Texas Technical University. Microbes were characterized using quantitative polymerase chain reaction where a total count of bacteria and fungi were determined. The primers that were used to determine the total count of bacteria and fungi were targeted for 16S rDNA genes and the internal transcribed spacer, respectively. PCR products were detected with SYBR Green I fluorescent dye and a melting curve analysis was performed to identify unique melt profiles resulting from DNA sequence variations from each species of the community. Results from both the total bacteria and total fungi count assays showed that distinct populations were present in isolates from these bioreactors. This was exhibited by variation in the number of peaks observed on the melting curve analysis graph. Further analysis of these results using species-specific primers will shed light on exactly which microbes are present in these effluents. Information gained from this study will enable the design of a system that can efficiently monitor microbes that play a role in the biogeochemical cycling of nitrogen in wastewater on the International Space Station to assist in the design of a sustainable system capable of converting this nutrient.

  12. Two Devices for Removing Sludge From Bioreactor Wastewater

    Science.gov (United States)

    Archer, Shivaun; Hitchens, G. DUncan; Jabs, Harry; Cross, Jennifer; Pilkinton, Michelle; Taylor, Michael

    2007-01-01

    Two devices a magnetic separator and a special filter denoted a self-regenerating separator (SRS) have been developed for separating sludge from the stream of wastewater from a bioreactor. These devices were originally intended for use in microgravity, but have also been demonstrated to function in normal Earth gravity. The magnetic separator (see Figure 1) includes a thin-walled nonmagnetic, stainless-steel cylindrical drum that rotates within a cylindrical housing. The wastewater enters the separator through a recirculation inlet, and about 80 percent of the wastewater flow leaves through a recirculation outlet. Inside the drum, a magnet holder positions strong permanent magnets stationary and, except near a recirculation outlet, close to the inner drum surface. To enable magnetic separation, magnetite (a ferromagnetic and magnetically soft iron oxide) powder is mixed into the bioreactor wastewater. The magnetite becomes incorporated into the sludge by condensation, onto the powder particles, of microbe flocks that constitute the sludge. As a result, the magnets inside the drum magnetically attract the sludge onto the outer surface of the drum.

  13. Biofouling control: Bacterial quorum quenching versus chlorination in membrane bioreactors.

    Science.gov (United States)

    Weerasekara, Nuwan A; Choo, Kwang-Ho; Lee, Chung-Hak

    2016-10-15

    Biofilm formation (biofouling) induced via cell-to-cell communication (quorum sensing) causes problems in membrane filtration processes. Chorine is one of the most common chemicals used to interfere with biofouling; however, biofouling control is challenging because it is a natural process. This study demonstrates biofouling control for submerged hollow fiber membranes in membrane bioreactors by means of bacterial quorum quenching (QQ) using Rhodococcus sp. BH4 with chemically enhanced backwashing. This is the first trial to bring QQ alongside chlorine injection into practice. A high chlorine dose (100 mg/L as Cl2) to the system is insufficient for preventing biofouling, but addition of the QQ bacterium is effective for disrupting biofouling that cannot be achieved by chlorination alone. QQ reduces the biologically induced metal precipitate and extracellular biopolymer levels in the biofilm, and biofouling is significantly delayed when QQ is applied in addition to chlorine dosing. QQ with chlorine injection gives synergistic effects on reducing physically and chemically reversible fouling resistances while saving substantial filtration energy. Manipulating microbial community functions with chemical treatment is an attractive tool for biofilm dispersal in membrane bioreactors.

  14. Engineering Tendon: Scaffolds, Bioreactors, and Models of Regeneration.

    Science.gov (United States)

    Youngstrom, Daniel W; Barrett, Jennifer G

    2016-01-01

    Tendons bridge muscle and bone, translating forces to the skeleton and increasing the safety and efficiency of locomotion. When tendons fail or degenerate, there are no effective pharmacological interventions. The lack of available options to treat damaged tendons has created a need to better understand and improve the repair process, particularly when suitable autologous donor tissue is unavailable for transplantation. Cells within tendon dynamically react to loading conditions and undergo phenotypic changes in response to mechanobiological stimuli. Tenocytes respond to ultrastructural topography and mechanical deformation via a complex set of behaviors involving force-sensitive membrane receptor activity, changes in cytoskeletal contractility, and transcriptional regulation. Effective ex vivo model systems are needed to emulate the native environment of a tissue and to translate cell-matrix forces with high fidelity. While early bioreactor designs have greatly expanded our knowledge of mechanotransduction, traditional scaffolds do not fully model the topography, composition, and mechanical properties of native tendon. Decellularized tendon is an ideal scaffold for cultivating replacement tissue and modeling tendon regeneration. Decellularized tendon scaffolds (DTS) possess high clinical relevance, faithfully translate forces to the cellular scale, and have bulk material properties that match natural tissue. This review summarizes progress in tendon tissue engineering, with a focus on DTS and bioreactor systems. PMID:26839559

  15. Thiosulphate conversion in a methane and acetate fed membrane bioreactor.

    Science.gov (United States)

    Suarez-Zuluaga, Diego A; Timmers, Peer H A; Plugge, Caroline M; Stams, Alfons J M; Buisman, Cees J N; Weijma, Jan

    2016-02-01

    The use of methane and acetate as electron donors for biological reduction of thiosulphate in a 5-L laboratory membrane bioreactor was studied and compared to disproportionation of thiosulphate as competing biological reaction. The reactor was operated for 454 days in semi-batch mode; 30 % of its liquid phase was removed and periodically replenished (days 77, 119, 166, 258, 312 and 385). Although the reactor was operated under conditions favourable to promote thiosulphate reduction coupled to methane oxidation, thiosulphate disproportionation was the dominant microbial process. Pyrosequencing analysis showed that the most abundant microorganisms in the bioreactor were phototrophic green sulphur bacteria (GSB) belonging to the family Chlorobiaceae and thiosulphate-disproportionating bacteria belonging to the genus Desulfocapsa. Even though the reactor system was surrounded with opaque plastic capable of filtering most of the light, the GSB used it to oxidize the hydrogen sulphide produced from thiosulphate disproportionation to elemental sulphur. Interrupting methane and acetate supply did not have any effect on the microbial processes taking place. The ultimate goal of our research was to develop a process that could be applied for thiosulphate and sulphate removal and biogenic sulphide formation for metal precipitation. Even though the system achieved in this study did not accomplish the targeted conversion using methane as electron donor, it does perform microbial conversions which allow to directly obtain elemental sulphur from thiosulphate. PMID:26423279

  16. Comparison between controlled landfill reactor and conditioned landfill bioreactor.

    Science.gov (United States)

    Luo, Feng; Chen, Wan-Zhi; Song, Fu-Zhong; Li, Xiao-Peng; Zhang, Guo-Qing

    2004-01-01

    Bioreactor landfills allow a more active landfill management that recognizes the biological, chemical and physical processes involved in a landfill environment. The laboratory-scale simulators of landfill reactors treating municipal solid wastes were studied, the effect of solid waste size, leachate recirculation, nutrient balance, pH value, moisture content and temperature on the rate of municipal solid waste (MSW) biodegradation were determined, and it indicated the optimum pH value, moisture content and temperature decomposing MSW. The results of waste biodegradation were compared with that of the leachate-recirculated landfill simulator and conservative sanitary landfill simulator. In the control experiment the antitheses of a decreasing trend of the organic load, measured as biological oxygen demand and chemical oxygen demand, was shown. An obvious enhancement of effective disposal from conservative sanitary landfill (CSL) simulator, to the leachate-recirculated landfill (LRL) simulator and to the conditioned bioreactor landfill (CBL) simulator would be noted, through displaying the compared results of solid waste settlement, heavy metal concentration in leachate, methane production rate, biogas composition, BOD and COD as well as their ratio. PMID:15559832

  17. Biological conversion of synthesis gas. Topical report: Bioreactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Basu, R.; Klasson, K.T.; Clausen, E.C.; Gaddy, J.L.

    1993-09-01

    The purpose of the proposed research is to develop a technically and economically feasible process for biologically producing H{sub 2} from synthesis gas while, at the same time, removing harmful sulfur gas compounds. Six major tasks are being studied: culture development, where the best cultures are selected and conditions optimized for simultaneous hydrogen production and sulfur gas removal; mass transfer and kinetic studies in which equations necessary for process design are developed; bioreactor design studies, where the cultures chosen in Task 1 are utilized in continuous reaction vessels to demonstrate process feasibility and define operating conditions; evaluation of biological synthesis gas conversion under limiting conditions in preparation for industrial demonstration studies; process scale-up where laboratory data are scaled to larger-size units in preparation for process demonstration in a pilot-scale unit; and economic evaluation, where process simulations are used to project process economics and identify high cost areas during sensitivity analyses. The purpose of this report is to present results from bioreactor studies involving H{sub 2} production by water gas shift and H{sub 2}S removal to produce elemental sulfur. Many of the results for H{sub 2} production by Rhodospirillum rubrum have been presented during earlier contracts. Thus, this report concentrates mainly on H{sub 2}S conversion to elemental sulfur by R. rubrum.

  18. Liste des abréviations et des sigles

    OpenAIRE

    2015-01-01

    AEF Afrique Équatoriale Française. AJCF Association Catholique de la Jeunesse Française. ALN Armée de Libération Nationale. AMGOT .Allied Military Government for Occupied Territories (administration militaire alliée des territoires occupés). AOF Afrique Occidentale Française. APEL Association des Parents d'élèves de l'École Libre. BBC British Broadcasting Corporation. CDL Comité Départemental de Libération. CDN Comité de Défense Nationale. CED Communauté Européenne de Défense. CEE Communauté ...

  19. Approvisionnement et gestion des silex

    Directory of Open Access Journals (Sweden)

    Christophe Delage

    2008-06-01

    Full Text Available Les études de provenance des vestiges présents sur les sites préhistoriques se sont particulièrement développées ces dernières années au Proche-Orient. Des matériaux tels que l’ocre, le basalte ou l’obsidienne, ont ainsi fait l’objet de caractérisations archéométriques détaillées. En ce qui concerne le silex, on savait qu’il était présent en abondance au nord d’Israël. Quelques rares études ponctuelles ont montré le potentiel de recherches sur l’origine et les méthodes de taille des silex pré...

  20. Development of a hybrid scaffold and a bioreactor for cartilage regeneration

    Institute of Scientific and Technical Information of China (English)

    LEE Seung-Jae; LEE In Hwan; PARK Jeong Hun; GWAK So-Jung; RHIE Jong-Won; CHO Dong-Woo; KO Tae Jo; KIM Dong Sung

    2009-01-01

    We developed a hybrid scaffold and a bioreactor for cartilage regeneration. The hybrid scaffold was developed as combination of two components: a biodegradable framework and hydrogel-containing chondrocytes. We performed the MTT cell proliferation assay to compare the proliferation and viability of chondrocytes on three types of scaffolds: an alginate gel, the hybrid scaffold, and an alginate sponge. Cells were encapsulated in 2% agarose gel. The bioreactor consisted of a circulation system and a compression system. We performed dynamic cell culture on these agarose gels in the bioreactor for 3 days.

  1. Tissue engineering bioreactor systems for applying physical and electrical stimulations to cells.

    Science.gov (United States)

    Jin, GyuHyun; Yang, Gi-Hoon; Kim, GeunHyung

    2015-05-01

    Bioreactor systems in tissue engineering applications provide various types of stimulation to mimic the tissues in vitro and in vivo. Various bioreactors have been designed to induce high cellular activities, including initial cell attachment, cell growth, and differentiation. Although cell-stimulation processes exert mostly positive effects on cellular responses, in some cases such stimulation can also have a negative effect on cultured cells. In this review, we discuss various types of bioreactor and the positive and negative effects of stimulation (physical, chemical, and electrical) on various cultured cell types.

  2. Example study for granular bioreactor stratification: Three-dimensional evaluation of a sulfate-reducing granular bioreactor

    Science.gov (United States)

    Hao, Tian-wei; Luo, Jing-hai; Su, Kui-zu; Wei, Li; Mackey, Hamish R.; Chi, Kun; Chen, Guang-Hao

    2016-01-01

    Recently, sulfate-reducing granular sludge has been developed for application in sulfate-laden water and wastewater treatment. However, little is known about biomass stratification and its effects on the bioprocesses inside the granular bioreactor. A comprehensive investigation followed by a verification trial was therefore conducted in the present work. The investigation focused on the performance of each sludge layer, the internal hydrodynamics and microbial community structures along the height of the reactor. The reactor substratum (the section below baffle 1) was identified as the main acidification zone based on microbial analysis and reactor performance. Two baffle installations increased mixing intensity but at the same time introduced dead zones. Computational fluid dynamics simulation was employed to visualize the internal hydrodynamics. The 16S rRNA gene of the organisms further revealed that more diverse communities of sulfate-reducing bacteria (SRB) and acidogens were detected in the reactor substratum than in the superstratum (the section above baffle 1). The findings of this study shed light on biomass stratification in an SRB granular bioreactor to aid in the design and optimization of such reactors. PMID:27539264

  3. La diversification des cultures : comment la promouvoir?

    OpenAIRE

    Meynard, Jean Marc; Charlier, Aude; Charrier, François; Fares, Mehand; Le Bail, Marianne; Magrini, Marie-Benoît; Messean, Antoine

    2015-01-01

    Dans le dernier demi-siècle, les territoires et les exploitations agricoles se sont de plus en plus spécialisés. Or, on sait aujourd’hui qu’une diversification des cultures serait nécessaire pour réduire l’usage des intrants (pesticides, engrais azotés, eau d’irrigation) et les nuisances environnementales associées. Cet article tente de mettre au jour les freins à la diversification des cultures, qui se manifestent à différents niveaux des filières agro industrielles, afin de dégager des pist...

  4. Les Sphingidae, probables pollinisateurs des baobabs malgaches

    OpenAIRE

    Ryckewaert, Philippe; Razanamaro, Onja; Rasoamanana, Elysée; Rakotoarimihaja, Tantelinirina; Ramavovololona, Perle; Danthu, Pascal

    2011-01-01

    Des comparaisons phénologiques et morphologiques des f leurs des six espèces de baobabs, Adansonia spp., endémiques de Madagascar et une étude des insectes visiteurs de ces fleurs ont été menées in situ afin d'identifier les pollinisateurs possibles de ces arbres. Les baobabs malgaches sont regroupés en deux sections en fonction de la lon- gueur de l'androcée (tube pollinique plus filet des étamines) : les Longitubae, A. za, A. rubrostipa, A. madagascariensis et A. perrieri, dont l'androcée v...

  5. Treatment of phenolics, aromatic hydrocarbons, and cyanide-bearing wastewater in individual and combined anaerobic, aerobic, and anoxic bioreactors.

    Science.gov (United States)

    Sharma, Naresh K; Philip, Ligy

    2015-01-01

    Studies were conducted on a mixture of pollutants commonly found in coke oven wastewater (CWW) to evaluate the biodegradation of various pollutants under anaerobic, aerobic, and anoxic conditions. The removal of the pollutants was monitored during individual bioreactor operation and using a combination of bioreactors operating in anaerobic-aerobic-anoxic sequence. While studying the performance of individual reactors, it was observed that cyanide removal (83.3 %) was predominant in the aerobic bioreactor, while much of the chemical oxygen demand (COD) (69 %) was consumed in the anoxic bioreactor. With the addition of cyanide, the COD removal efficiency was affected in all the bioreactors, and several intermediates were detected. While treating synthetic CWW using the combined bioreactor system, the overall COD removal efficiency was 86.79 % at an OLR of 2.4 g COD/L/day and an HRT of 96 h. The removal efficiency of 3,5-xylenol and cyanide, with inlet concentration of 150 and 10 mg/L, was found to be 91.8 and 93.6 % respectively. It was found that the impact of xylenol on the performance of the bioreactors was less than cyanide toxicity. Molecular analysis using T-RFLP revealed the dominance of strictly aerobic, mesophilic proteobacterium, Bosea minatitlanensis, in the aerobic bioreactor. The anoxic bioreactor was dominant with Rhodococcus pyridinivorans, known for its remarkable aromatic decomposing activity, while an unclassified Myxococcales bacterium was identified as the predominant bacterial species in the anaerobic bioreactor.

  6. Arsenic removal in a sulfidogenic fixed-bed column bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Altun, Muslum, E-mail: muslumaltun@hotmail.com [Hacettepe University, Department of Chemistry, Beytepe, Ankara (Turkey); Sahinkaya, Erkan [Istanbul Medeniyet University, Bioengineering Department, Goztepe, Istanbul (Turkey); Durukan, Ilknur; Bektas, Sema [Hacettepe University, Department of Chemistry, Beytepe, Ankara (Turkey); Komnitsas, Kostas [Technical University of Crete, Department of Mineral Resources Engineering, Chania (Greece)

    2014-03-01

    Highlights: • Sulfidogenic treatment of As-containing AMD was investigated. • High rate simultaneous removal of As and Fe was achieved. • As was removed without adding alkalinity or adjusting pH. • As and Fe removal mechanisms were elucidated. - Abstract: In the present study, the bioremoval of arsenic from synthetic acidic wastewater containing arsenate (As{sup 5+}) (0.5–20 mg/L), ferrous iron (Fe{sup 2+}) (100–200 mg/L) and sulfate (2000 mg/L) was investigated in an ethanol fed (780–1560 mg/L chemical oxygen demand (COD)) anaerobic up-flow fixed bed column bioreactor at constant hydraulic retention time (HRT) of 9.6 h. Arsenic removal efficiency was low and averaged 8% in case iron was not supplemented to the synthetic wastewater. Neutral to slightly alkaline pH and high sulfide concentration in the bioreactor retarded the precipitation of arsenic. Addition of 100 mg/L Fe{sup 2+} increased arsenic removal efficiency to 63%. Further increase of influent Fe{sup 2+} concentration to 200 mg/L improved arsenic removal to 85%. Decrease of influent COD concentration to its half, 780 mg/L, resulted in further increase of As removal to 96% when Fe{sup 2+} and As{sup 5+} concentrations remained at 200 mg/L and 20 mg/L, respectively. As a result of the sulfidogenic activity in the bioreactor the effluent pH and alkalinity concentration averaged 7.4 ± 0.2 and 1736 ± 239 mg CaCO{sub 3}/L respectively. Electron flow from ethanol to sulfate averaged 72 ± 10%. X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses were carried out to identify the nature of the precipitate generated by sulfate reducing bacteria (SRB) activity. Precipitation of arsenic in the form of As{sub 2}S{sub 3} (orpiment) and co-precipitation with ferrous sulfide (FeS), pyrite (FeS{sub 2}) or arsenopyrite (FeAsS) were the main arsenic removal mechanisms.

  7. Greenhouse Gas Emission from In-situ Denitrifying Bioreactors

    Science.gov (United States)

    Pluer, W.; Walter, M. T.; Geohring, L.

    2013-12-01

    Despite decades of concerted effort to mitigate nonpoint source nitrate (NO3-) pollution from agricultural lands, these efforts have not been sufficient to arrest eutrophication, which continues to be a serious and chronic problem. Two primary processes for removing excess NO3- from water are biological assimilation and denitrification. Denitrifying bacteria use NO3- as the electron acceptor for respiration in the absence of oxygen. Denitrification results in reduced forms of nitrogen, often dinitrogen gas (N2) but also nitrous oxide (N2O), an aggressive greenhouse gas (GHG). A promising solution to NO3- pollution is to intercept agricultural discharges with denitrifying bioreactors (DNBRs), though research has been limited to NO3- level reduction and omitted process mechanisms. DNBRs work by providing an anaerobic environment with plenty of organic matter (commonly woodchips) for denitrifying bacteria to flourish. While, initial results from bioreactor studies show that they can cost-effectively remove NO3-, GHG emission could be an unintended consequence. The study's goal is to determine how bioreactor design promotes microbial denitrification while limiting N2O production. It specifically focuses on expanding the body of knowledge concerning DNBRs in the areas of design implications and internal processes by measuring intermediate compounds and not solely NO3-. Nutrient samples are collected at inflow and outflow structures and tested for NO3- and nitrite (NO2-). Dissolved and headspace gas samples are collected and tested for N2O. Additional gas samples will be analyzed for naturally-occurring isotopic N2 to support proposed pathways. Designs will be analyzed both through the N2O/N2 production ratio and NO2- production caused by various residence times and inflow NO3- concentrations. High GHG ratios and NO2- production suggest non-ideal conditions or flow patterns for complete denitrification. NO3- reduction is used for comparison with previous studies. Few

  8. Toward the Standardization of Bioreactors for Space Research

    Science.gov (United States)

    Garcia, Michel; Nebuloni, Stefano; Dainesi, Paolo; Gass, Samuel

    Growing interest in long-term human space missions and exploration as well as future plans for extra-terrestrial human settlements, places increasing importance on understanding biological and chemical processes in space at cellular and molecular level. RUAG Space has been involved in the development of bioreactors for life-science experiments in space for the past 20 years. Throughout these developments, RUAG has acted as the link between scientists and the space industry, translating high-level scientific requirements into technical requirements, verifying their feasibility within the space context, and developing state-of-the-art experiment hardware which can interface with dedicated micro-gravity platform. Although this approach has brought forth promising developments in the field, it is associated to very long development phases as well as correspondingly high costs. Each new scientific experiment is often associated to an entirely new hardware development. This is, in large, due to the limited information available on the possibilities and constraints imposed by the particular context of space. Therefore, a considerable amount of time and development costs are invested in order to accommodate stringent scientific requirements and/or specific experiment design in space hardware. This does not only have an impact on funding opportunities for micro-gravity experiments in space, it also curbs the pace of scientific discoveries and limits the number of research opportunities. Therefore, in the following, we present an overview of already established possibilities for cellular research in space, with special emphasis on hardware developed by RUAG Space. This is intended to provide scientists with key technical information on already existing bioreactors, subsystems, and components, which may be used as a basis when designing scientific studies. By considering this information from the onset of the establishment of scientific requirements, technical solutions can

  9. Etude des erreurs d'estimation des populations par la méthode des captures successives (DeLURY, 2 captures et des captures-recaptures (PETERSEN

    Directory of Open Access Journals (Sweden)

    LAURENT M.

    1978-01-01

    Full Text Available L'estimation des populations naturelles par capture-recapture et par captures successives est souvent entachée d'erreur car, dans de nombreux cas, l'hypothèse fondamentale d'égalité des probabilités de captures pour tous les individus dans le temps et dans l'espace n'est pas respectée. Dans le cas des populations de poissons envisagés ici, les captures ont lieu par la pêche électrique. On a pu chiffrer l'ordre de grandeur des erreurs systématiques faites sur l'estimation des peuplements, en fonction des conditions particulières, biotiques et abiotiques, des différents milieux inventoriés.

  10. Method and Apparatus for a Miniature Bioreactor System for Long-Term Cell Culture

    Science.gov (United States)

    Kleis, Stanley J. (Inventor); Geffert, Sandra K. (Inventor); Gonda, Steve R. (Inventor)

    2015-01-01

    A bioreactor and method that permits continuous and simultaneous short, moderate, or long term cell culturing of one or more cell types or tissue in a laminar flow configuration is disclosed, where the bioreactor supports at least two laminar flow zones, which are isolated by laminar flow without the need for physical barriers between the zones. The bioreactors of this invention are ideally suited for studying short, moderate and long term studies of cell cultures and the response of cell cultures to one or more stressors such as pharmaceuticals, hypoxia, pathogens, or any other stressor. The bioreactors of this invention are also ideally suited for short, moderate or long term cell culturing with periodic cell harvesting and/or medium processing for secreted cellular components.

  11. Biodegradation of the water-soluble gasoline components in a novel hybrid bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-De-Jesus, A.; Lara-Rodriguez, A.; Santoyo-Tepole, F.; Juarez-Ramirez, C.; Cristiani-Urbina, E.; Ruiz-Ordaz, N.; Galindez Mayer, J. [Escuela Nacional de Ciencias Biologicas, del Instituto Politecnico Nacional, Departamento de Ingenieria Bioquimica, Carpio y Plan de Ayala, ' ' Centro Operativo Naranjo' ' , Mexico, D.F. (Mexico)

    2003-07-01

    A novel hybrid bioreactor was designed to remove volatile organic compounds from water contaminated with water-soluble gasoline components, and the performance of this new bioreactor was investigated. It was composed of two biotrickling filter sections and one biofilter section. The liquid phase pollutants were removed by a mixed culture in the biotrickling filter sections and the gas phase pollutants stripped by air injection in the biofilter section. The specific rates of chemical oxygen demand (COD) removal obtained in the reactor were directly proportional to the pollutant-loading rate. A stable operation of the hybrid bioreactor was attained for long periods of time. The bioreactor had the potential to simultaneously treat a complex mixture of volatile organic compounds, e.g., those present in the water-soluble fraction of gasoline, as well as the capacity to readily adapt to changing operational conditions, such as an increased contaminant loading, and variations in the airflow rate. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  12. NOVEL CERAMIC MEMBRANE BIOREACTOR FOR LOW-FLOW SYSTEMS - PHASE I

    Science.gov (United States)

    Improved low-flow (50,000 gallons per day) sanitary wastewater treatment systems are needed. CeraMem Corporation's proposed approach includes a membrane bioreactor (MBR) using fully proven biological processes for biological oxygen demand oxidation and (optionally) fo...

  13. Bioreactors as Engineering Support to Treat Cardiac Muscle and Vascular Disease

    Directory of Open Access Journals (Sweden)

    Diana Massai

    2013-01-01

    Full Text Available Cardiovascular disease is the leading cause of morbidity and mortality in the Western World. The inability of fully differentiated, load-bearing cardiovascular tissues to in vivo regenerate and the limitations of the current treatment therapies greatly motivate the efforts of cardiovascular tissue engineering to become an effective clinical strategy for injured heart and vessels. For the effective production of organized and functional cardiovascular engineered constructs in vitro, a suitable dynamic environment is essential, and can be achieved and maintained within bioreactors. Bioreactors are technological devices that, while monitoring and controlling the culture environment and stimulating the construct, attempt to mimic the physiological milieu. In this study, a review of the current state of the art of bioreactor solutions for cardiovascular tissue engineering is presented, with emphasis on bioreactors and biophysical stimuli adopted for investigating the mechanisms influencing cardiovascular tissue development, and for eventually generating suitable cardiovascular tissue replacements.

  14. Numerical Simulation of Microcarrier Motion in a Rotating Wall Vessel Bioreactor

    Institute of Scientific and Technical Information of China (English)

    ZHI-HAO JU; TIAN-QING LIU; XUE-HU MA; ZHAN-FENG CUI

    2006-01-01

    Objective To analyze the forces of rotational wall vessel (RWV) bioreactor on small tissue pieces or microcarrier particles and to determine the tracks of microcarrier particles in RWV bioreactor. Methods The motion of the microcarrier in the rotating wall vessel (RWV) bioreactor with both the inner and outer cylinders rotating was modeled by numerical simulation. Results The continuous trajectory of microcarrier particles, including the possible collision with the wall was obtained. An expression between the minimum rotational speed difference of the inner and outer cylinders and the microcarrier particle or aggregate radius could avoid collisions with either wall. The range of microcarrier radius or tissue size, which could be safely cultured in the RWV bioreactor, in terms of shear stress level, was determined. Conclusion The model works well in describing the trajectory of a heavier microcarrier particle in rotating wall vessel.

  15. Optimal Homogenization of Perfusion Flows in Microfluidic Bio-Reactors: A Numerical Study

    DEFF Research Database (Denmark)

    Okkels, Fridolin; Dufva, Martin; Bruus, Henrik

    2011-01-01

    In recent years, the interest in small-scale bio-reactors has increased dramatically. To ensure homogeneous conditions within the complete area of perfused microfluidic bio-reactors, we develop a general design of a continually feed bio-reactor with uniform perfusion flow. This is achieved...... by introducing a specific type of perfusion inlet to the reaction area. The geometry of these inlets are found using the methods of topology optimization and shape optimization. The results are compared with two different analytic models, from which a general parametric description of the design is obtained...... and tested numerically. Such a parametric description will generally be beneficial for the design of a broad range of microfluidic bioreactors used for, e. g., cell culturing and analysis and in feeding bio-arrays....

  16. Efficacy of Aspergillus sp. for degradation of chlorpyrifos in batch and continuous aerated packed bed bioreactors.

    Science.gov (United States)

    Yadav, Maya; Srivastva, Navnita; Shukla, Awadhesh Kumar; Singh, Ram Sharan; Upadhyay, Siddh Nath; Dubey, Suresh Kumar

    2015-01-01

    Aerobic biodegradation of chlorpyrifos (CP) by Aspergillus sp. was investigated in batch and continuous packed bed bioreactors. The optimal process parameters for achieving the maximum removal efficiency (RE), determined using a batch bioreactor packed with polyurethane foam pieces, were inoculum level: 2.5 mg (wet weight) mL(-1), pH 7.0, temperature 28 °C, DO 5.8 mg L(-1), and CP concentration 300 mg L(-1). The continuous packed bed bioreactor was operated at flow rates ranging from 10 to 40 mL h(-1) while keeping other parameters at their optimal level. Steady-state CP removal efficiencies greater than 85 % were obtained up to the inlet loading of 180 mg L(-1) d(-1). The continuous bioreactor behaved as a plug flow unit and was able to stabilize quickly after perturbation in the inlet loading.

  17. Characterizing protein modifications by reactive metabolites using magnetic bead bioreactors and LC-MS/MS.

    Science.gov (United States)

    Li, Dandan; Fu, You-Jun; Rusling, James F

    2015-03-18

    We report here label-free metabolite-protein adduct detection and identification employing magnetic beads coated with metabolic enzymes as bioreactors to generate metabolites and possible metabolite-protein adducts for analysis by liquid chromatography-tandem mass spectrometry.

  18. Recherche des oscillations de Neutrinos $\

    CERN Document Server

    Gangler, E

    1997-01-01

    Le detecteur nomad, place sur le faisceau de neutrinos wide-band-beam du sps, de contamination en neutrino tau marginale, permet de rechercher des oscillations neutrino muon - tau dans la region de pertinence cosmologique et de distinguer statistiquement les courants charges des neutrinos tau essentiellement par leur mesure cinematique. Une large part du travail de these a donc ete consacree a la reconstruction des evenements dans les chambres a derive, cible instrumentee et cur de l'experience, dont la physique de detection est decrite. Une methode de recherche de traces fut developpee, utilisant certaines informations d'un autre sous-detecteur de nomad, le trd. Pour combler une perte d'efficacite de reconstruction, une methode de recherche de traces courtes s'appuyant sur des vertex deja constitues fut developpee en exploitant les potentialites du filtre de kalman, algorithme iteratif d'ajustement de traces. Ces methodes sont utilisees en production par la collaboration. Cette these porte sur la recherche d...

  19. Les parcs des porcelainiers Haviland

    Directory of Open Access Journals (Sweden)

    Colette Chabrely

    2012-04-01

    Full Text Available Les parcs du Reynou et de Mont-Méry en Limousin, anciennes propriétés des porcelainiers Haviland, présentent l’un et l’autre un grand intérêt paysager et botanique. Dans les deux cas, l’attribution de la création est incertaine. Cet article propose pour le Reynou une analyse de documents figurés anciens permettant de préciser la chronologie des travaux du château et du parc. Pour Mont-Méry il s’agit de poser de nouveaux jalons pour une étude plus approfondie des sources et de la composition des jardins afin d’envisager de nouvelles pistes pour leur attribution.The Reynou and Mont-Méry parks near Limoges originally belonged to the city’s porcelain manufacturers, the Havilands. Both parks are of considerable interest in terms of their landscaping and their botany. In both cases, there is some uncertainty as to the identity of their designers. This article offers an analysis of the graphic representations of the Reynou park, clarifying the chronology of the creation of the château and its park. For the Mont-Méry park, the aim is to offer some guidelines for further research in the source material and on the design of the park itself, perhaps allowing for the designer to be identified.

  20. Reduction des effectifs ou licenciements

    CERN Multimedia

    Maiani, Luciano

    2002-01-01

    "Vous faites un amalgame entre la reduction en cours des effectifs du CERN (organisation europeenne pour la recherche nucleaire) et les economies que le laboratoire doit realiser dans les cinq ans a venir pour financer le projet de grand collisionneur de hadrons (Le Monde du 4 septembre)" (1/2 page).

  1. Osteoporose - die Sicht des Radiologen

    Directory of Open Access Journals (Sweden)

    Grampp S

    1998-01-01

    Full Text Available Die frühe Diagnose der Osteoporose und eine akkurate Beurteilung von Behandlungserfolgen stehen im Mittelpunkt der radiologischen Bemühungen. Die häufigsten angewendeten Methoden, um das periphere Skelett sowie das Achsenskelett zu beurteilen, sind die Zwei-Spektren-Röntgenabsorptiometrie, die quantitative Computertomographie und der quantitative Ultraschall. Generell werden die Meßergebnisse eines Individuums mit einer alters-, geschlechts-, und rassenspezifischen Kontrollgruppe verglichen. In diesem Zusammenhang ist die Bestimmung der Knochenmasse ein Indikator des künftigen Frakturrisikos eines Patienten. Die radiologische Diagnose der Osteoporose kann durch die Bestimmung der Knochenmasse erfolgen, auch wenn keine prävalenten Frakturen vorliegen. Das Frakturrisiko für den Meßwert eines Individuums steigt um etwa das 1,5 bis 2,5-fache für jede Standardabweichung (SD unter der Spitzenknochenmasse der Normbevölkerung (T-score. Die Wahl des Meßortes und der Untersuchungstechnik zur Bestimmung der Knochenmasse oder des Frakturrisikos muß sich nach individuellen Gegebenheiten des Patienten sowie den Stärken und Limitationen der Techniken richten.

  2. Bangalore, ville des nouvelles technologies

    Directory of Open Access Journals (Sweden)

    Clarisse Didelon

    2003-06-01

    Full Text Available Bangalore est devenue la Silicon Valley de l’Inde. Une partie de ses habitants y vit à l’occidentale mais le reste de la population souffre de la croissance spectaculaire de la ville. Face à l’insuffisance des infrastructures, Bangalore devient de moins en moins attractive pour les entreprises internationales.

  3. Mill Seat Landfill Bioreactor Renewable Green Power (NY)

    Energy Technology Data Exchange (ETDEWEB)

    Barton & Loguidice, P.C.

    2010-01-07

    The project was implemented at the Mill Seat landfill located in the Town of Bergen, Monroe County, New York. The landfill was previously equipped with a landfill gas collection system to collect methane gas produced by the bioreactor landfill and transport it to a central location for end use. A landfill gas to energy facility was also previously constructed at the site, which utilized generator engines, designed to be powered with landfill methane gas, to produce electricity, to be utilized on site and to be sold to the utility grid. The landfill gas generation rate at the site had exceeded the capacity of the existing generators, and the excess landfill gas was therefore being burned at a candlestick flare for destruction. The funded project consisted of the procurement and installation of two (2) additional 800 KW Caterpillar 3516 generator engines, generator sets, switchgear and ancillary equipment.

  4. Plasmid maintenance and protein overproduction in selective recycle bioreactors.

    Science.gov (United States)

    Ogden, K L; Davis, R H

    1991-02-20

    A new plasmid construct has been used in conjunction with selective recycle to successfully maintain otherwise unstable plasmid-bearing E. coli cells in a continuous bioreactor and to produce significant amounts of the plasmid-encoded protein beta-lactamase. The plasmid is constructed so that pilin expression, which leads to bacterial flocculation, is under control of the tac operon. The plasmid-bearing cells are induced to flocculate in the separator, whereas cell growth and product synthesis occur in the main fermentation vessel without the inhibiting effects of pilin production. Selective recycle allows for the maintenance of the plasmid-bearing cells by separating flocculent, plasmid-bearing cells from nonflocculent, segregant cells in an inclined settler, and recycling only the plasmid-bearing cells to the reactor. As a result, product expression levels are maintained that are more than ten times the level achieved without selective recycle. All experimental data agree well with theoretical predictions. PMID:18597374

  5. Ceramic Ultra Filtration Membrane Bioreactor for Domestic Wastewater Treatment

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A long term domestic wastewater treatment experiment was conducted using a recirculating ceramic ultra filtration membrane bioreactor (CUFMB) system. Three experiments were run with a hydraulic retention time of 5h, sludge retention times of 5d, 15d, and 30d and a membrane surface flow rate of 4m/s. The experiment studied the membrane fouling mechanism and cleaning techniques. The results show that a CUFMB system can provide continuous good quality effluent which is completely acceptable for reuse. The system is also not affected by fluctuations of the inlet flow. The CUFMB sludge loading rate is similar to that of conventional biological treatment units. However, the volumetric loading rate of the CUFMB is 24 times that of conventional biological treatment units. Membrane fouling occurs due to channel clogging, which could be easily removed, and surface fouling, which can be effectively removed using the method described in this work which includes water rinsing, base cleaning, and acid washing.

  6. Phase separated membrane bioreactor - Results from model system studies

    Science.gov (United States)

    Petersen, G. R.; Seshan, P. K.; Dunlop, E. H.

    1989-01-01

    The operation and evaluation of a bioreactor designed for high intensity oxygen transfer in a microgravity environment is described. The reactor itself consists of a zero headspace liquid phase separated from the air supply by a long length of silicone rubber tubing through which the oxygen diffuses in and the carbon dioxide diffuses out. Mass transfer studies show that the oxygen is film diffusion controlled both externally and internally to the tubing and not by diffusion across the tube walls. Methods of upgrading the design to eliminate these resistances are proposed. Cell growth was obtained in the fermenter using Saccharomyces cerevisiae showing that this concept is capable of sustaining cell growth in the terrestrial simulation.

  7. Model system studies with a phase separated membrane bioreactor

    Science.gov (United States)

    Petersen, G. R.; Seshan, P. K.; Dunlop, Eric H.

    1989-01-01

    The operation and evaluation of a bioreactor designed for high intensity oxygen transfer in a microgravity environment is described. The reactor itself consists of a zero headspace liquid phase separated from the air supply by a long length of silicone rubber tubing through which the oxygen diffuses in and the carbon dioxide diffuses out. Mass transfer studies show that the oxygen is film diffusion controlled both externally and internally to the tubing and not by diffusion across the tube walls. Methods of upgrading the design to eliminate these resistances are proposed. Cell growth was obtained in the fermenter using Saccharomyces cerevisiae showing that this concept is capable of sustaining cell growth in the terrestial simulation.

  8. Phase separated membrane bioreactor: Results from model system studies

    Science.gov (United States)

    Petersen, G. R.; Seshan, P. K.; Dunlop, E. H.

    The operation and evaluation of a bioreactor designed for high intensity oxygen transfer in a microgravity environment is described. The reactor itself consists of a zero headspace liquid phase separated from the air supply by a long length of silicone rubber tubing through which the oxygen diffuses in and the carbon dioxide diffuses out. Mass transfer studies show that the oxygen is film diffusion controlled both externally and internally to the tubing and not by diffusion across the tube walls. Methods of upgrading the design to eliminate these resistances are proposed. Cell growth was obtained in the fermenter using Saccharomyces cerevisiae showing that this concept is capable of sustaining cell growth in the terrestial simulation.

  9. Instrumentation, control, and automation for submerged anaerobic membrane bioreactors.

    Science.gov (United States)

    Robles, Ángel; Durán, Freddy; Ruano, María Victoria; Ribes, Josep; Rosado, Alfredo; Seco, Aurora; Ferrer, José

    2015-01-01

    A submerged anaerobic membrane bioreactor (AnMBR) demonstration plant with two commercial hollow-fibre ultrafiltration systems (PURON®, Koch Membrane Systems, PUR-PSH31) was designed and operated for urban wastewater treatment. An instrumentation, control, and automation (ICA) system was designed and implemented for proper process performance. Several single-input-single-output (SISO) feedback control loops based on conventional on-off and PID algorithms were implemented to control the following operating variables: flow-rates (influent, permeate, sludge recycling and wasting, and recycled biogas through both reactor and membrane tanks), sludge wasting volume, temperature, transmembrane pressure, and gas sparging. The proposed ICA for AnMBRs for urban wastewater treatment enables the optimization of this new technology to be achieved with a high level of process robustness towards disturbances. PMID:25635702

  10. Fouling Characteristics and Prevention Techniques for Membrane Bioreactor

    Institute of Scientific and Technical Information of China (English)

    LU Hua; WANG Zhi-qiang; YANG Jin-ying

    2005-01-01

    Membrane fouling is the main problem of membrane bioreactors (MBR), which seriously influences its wastewater treatment effect and running. The characteristics of microbiology and hydrodynamics concerning membrane fouling were investigated and the measure was put forward for optimum operation of MBR. The measure is that 1) the parameters of activated sludge concentration (X) and membrane flux should be lower than the critical values of X and membrane flux respectively, and 2) the activated sludge should be discharged periodically. The experimental results show that the combination backwashing of gas and permeated effluent is better than single gas backwashing or single permeated effluent backwashing. This technique can remove the cake layer deposited on the membrane surface, decrease the membrane fouling, and recover the membrane flux effectively. So it is effective for prevention of membrane fouling.

  11. Hybrid modeling of xanthan gum bioproduction in batch bioreactor.

    Science.gov (United States)

    Zabot, Giovani L; Mecca, Jaqueline; Mesomo, Michele; Silva, Marceli F; Prá, Valéria Dal; de Oliveira, Débora; Oliveira, J Vladimir; Castilhos, Fernanda; Treichel, Helen; Mazutti, Marcio A

    2011-10-01

    This work is focused on hybrid modeling of xanthan gum bioproduction process by Xanthomonas campestris pv. mangiferaeindicae. Experiments were carried out to evaluate the effects of stirred speed and superficial gas velocity on the kinetics of cell growth, lactose consumption and xanthan gum production in a batch bioreactor using cheese whey as substrate. A hybrid model was employed to simulate the bio-process making use of an artificial neural network (ANN) as a kinetic parameter estimator for the phenomenological model. The hybrid modeling of the process provided a satisfactory fitting quality of the experimental data, since this approach makes possible the incorporation of the effects of operational variables on model parameters. The applicability of the validated model was investigated, using the model as a process simulator to evaluate the effects of initial cell and lactose concentration in the xanthan gum production.

  12. Treatment of dairy wastewater with a membrane bioreactor

    Directory of Open Access Journals (Sweden)

    L. H. Andrade

    2013-12-01

    Full Text Available Among the food industries, the dairy industry is considered to be the most polluting one because of the large volume of wastewater generated and its high organic load. In this study, an aerobic membrane bioreactor (MBR was used for the treatment of wastewater from a large dairy industry and two hydraulic retention times (HRT, 6 and 8 hours, were evaluated. For both HRTs removal efficiencies of organic matter of 99% were obtained. Despite high permeate flux (27.5 L/h.m², the system operated fairly stablely. The molecular weight distribution of feed, permeate and mixed liquor showed that only the low molecular weight fraction is efficiently degraded by biomass and that the membrane has an essential role in producing a permeate of excellent quality.

  13. Decolourisation of textile wastewater in a submerged anaerobic membrane bioreactor.

    Science.gov (United States)

    Spagni, Alessandro; Casu, Stefania; Grilli, Selene

    2012-08-01

    Azo dye decolourisation can be easily achieved by biological reduction under anaerobic conditions. The aim of this study was to evaluate the applicability of submerged anaerobic membrane bioreactors (SAMBRs) for the decolourisation of dyeing wastewater containing azo dyes. The reactive orange 16 was used as model of an azo dye. The results demonstrated that very high decolourisation (higher than 99%) can be achieved by SAMBRs. Although decolourisation was not significantly influenced by the azo dye concentrations up to 3.2 g L(-1), methane production was greatly inhibited (up to 80-85%). Since volatile fatty acids accumulated in the treatment system with the azo dye concentration increase, methanogenes seem to be the most sensitive microbial populations of the anaerobic ecological community. The results demonstrated that anaerobic process combined with membrane filtration can deal with highly concentrated wastewaters that result from stream separation of industrial discharges.

  14. Application of gain scheduling to the control of batch bioreactors

    Science.gov (United States)

    Cardello, Ralph; San, Ka-Yiu

    1987-01-01

    The implementation of control algorithms to batch bioreactors is often complicated by the inherent variations in process dynamics during the course of fermentation. Such a wide operating range may render the performance of fixed gain PID controllers unsatisfactory. In this work, a detailed study on the control of batch fermentation is performed. Furthermore, a simple batch controller design is proposed which incorporates the concept of gain-scheduling, a subclass of adaptive control, with oxygen uptake rate as an auxiliary variable. The control of oxygen tension in the biorector is used as a vehicle to convey the proposed idea, analysis and results. Simulation experiments indicate significant improvement in controller performance can be achieved by the proposed approach even in the presence of measurement noise.

  15. Hydrodynamic effects on cell growth in agitated microcarrier bioreactors

    Science.gov (United States)

    Cherry, Robert S.; Papoutsakis, E. Terry

    1988-01-01

    The net growth rate of bovine embryonic kidney cells in microcarrier bioreactor is the result of a variable death rate imposed on a cell culture trying to grow at a constant intrinsic growth rate. The death rate is a function of the agitation conditions in the system, and increases at higher agitation because of increasingly energetic interactions of the cell covered microcarriers with turbulent eddies in the fluid. At very low agitation rates bead-bead bridging becomes important; the large clumps formed by bridging can interact with larger eddies than single beads, leading to a higher death rate at low agitation. The growth and death rate were correlated with a dimensionless eddy number which compares eddy forces to the buoyant force on the bead.

  16. Effects of superficial gas velocity on process dynamics in bioreactors

    Science.gov (United States)

    Devi, T. T.; Kumar, B.

    2014-06-01

    Present work analyzes the flow hydrodynamics and mass transfer mechanisms in double Rushton and CD-6 impeller on wide range (0.0075-0.25 m/s) of superficial gas velocity ( v g) in a gas-liquid phase bioreactor by employing computational fluid dynamics (CFD) technique. The volume averaged velocity magnitude and dissipation rate are found higher with increasing superficial gas velocity. Higher relative power draw ( P g/ P 0) is predicted in CD-6 than the Rushton impeller but no significant difference in volume averaged mass transfer coefficient ( k L a) observed between these two types of impeller. The ratio of power draw with mass transfer coefficient has been found higher in CD-6 impeller (25-50 %) than the Rushton impeller.

  17. Instrumentation, control, and automation for submerged anaerobic membrane bioreactors.

    Science.gov (United States)

    Robles, Ángel; Durán, Freddy; Ruano, María Victoria; Ribes, Josep; Rosado, Alfredo; Seco, Aurora; Ferrer, José

    2015-01-01

    A submerged anaerobic membrane bioreactor (AnMBR) demonstration plant with two commercial hollow-fibre ultrafiltration systems (PURON®, Koch Membrane Systems, PUR-PSH31) was designed and operated for urban wastewater treatment. An instrumentation, control, and automation (ICA) system was designed and implemented for proper process performance. Several single-input-single-output (SISO) feedback control loops based on conventional on-off and PID algorithms were implemented to control the following operating variables: flow-rates (influent, permeate, sludge recycling and wasting, and recycled biogas through both reactor and membrane tanks), sludge wasting volume, temperature, transmembrane pressure, and gas sparging. The proposed ICA for AnMBRs for urban wastewater treatment enables the optimization of this new technology to be achieved with a high level of process robustness towards disturbances.

  18. Membrane bioreactors in waste water treatment - status and trends

    Energy Technology Data Exchange (ETDEWEB)

    Kraume, M. [Technische Universitaet Berlin, Chair of Chemical and Process Engineering, Berlin (Germany); Drews, A. [HTW Berlin, FB II, Life Science Engineering, Berlin (Germany)

    2010-08-15

    Due to their unique advantages like controlled biomass retention, improved effluent quality, and decreased footprint, membrane bioreactors (MBRs) are being increasingly used in waste water treatment up to a capacity of several 100,000 p.e. This article reviews the current status of MBRs and reports trends in MBR design and operation. Typical operational and design parameters are given as well as guidelines for waste water treatment plant revamping. To further improve the biological performance, specific or hybrid process configurations are shown to lead to, e.g., enhanced nutrient removal. With regards to reducing membrane fouling, optimized modules, advanced control, and strategies like the addition of flux enhancers are currently emerging. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  19. Flexible Community Structure Correlates with Stable Community Function in Methanogenic Bioreactor Communities Perturbed by Glucose

    OpenAIRE

    Fernandez, Ana S.; Hashsham, Syed A.; Dollhopf, Sherry L.; Raskin, Lutgarde; Glagoleva, Olga; Dazzo, Frank B.; Hickey, Robert F.; Criddle, Craig S.; Tiedje, James M.

    2000-01-01

    Methanogenic bioreactor communities were used as model ecosystems to evaluate the relationship between functional stability and community structure. Replicated methanogenic bioreactor communities with two different community structures were established. The effect of a substrate loading shock on population dynamics in each microbial community was examined by using morphological analysis, small-subunit (SSU) rRNA oligonucleotide probes, amplified ribosomal DNA (rDNA) restriction analysis (ARDR...

  20. A comparative study of leachate quality and biogas generation in simulated anaerobic and hybrid bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qiyong; Tian, Ying; Wang, Shen; Ko, Jae Hac, E-mail: jaehacko@pkusz.edu.cn

    2015-07-15

    Highlights: • Temporary aeration shortened the initial acid inhibition phase for methanogens. • COD decreased faster in the hybrid bioreactor than that in the anaerobic control. • Methane generations from hybrid bioreactors were 133.4 L/kg{sub vs} and 113.2 L/kg{sub vs}. • MSW settlement increased with increasing the frequency of intermittent aeration. - Abstract: Research has been conducted to compare leachate characterization and biogas generation in simulated anaerobic and hybrid bioreactor landfills with typical Chinese municipal solid waste (MSW). Three laboratory-scale reactors, an anaerobic (A1) and two hybrid bioreactors (C1 and C2), were constructed and operated for about 10 months. The hybrid bioreactors were operated in an aerobic–anaerobic mode with different aeration frequencies by providing air into the upper layer of waste. Results showed that the temporary aeration into the upper layer aided methane generation by shortening the initial acidogenic phase because of volatile fatty acids (VFAs) reduction and pH increase. Chemical oxygen demand (COD) decreased faster in the hybrid bioreactors, but the concentrations of ammonia–nitrogen in the hybrid bioreactors were greater than those in the anaerobic control. Methanogenic conditions were established within 75 d and 60 d in C1 and C2, respectively. However, high aeration frequency led to the consumption of organic matters by aerobic degradation and resulted in reducing accumulative methane volume. The temporary aeration enhanced waste settlement and the settlement increased with increasing the frequency of aeration. Methane production was inhibited in the anaerobic control; however, the total methane generations from hybrid bioreactors were 133.4 L/kg{sub vs} and 113.2 L/kg{sub vs}. As for MSW with high content of food waste, leachate recirculation right after aeration stopped was not recommended due to VFA inhibition for methanogens.

  1. Protein Expression in Insect and Mammalian Cells Using Baculoviruses in Wave Bioreactors.

    Science.gov (United States)

    Kadwell, Sue H; Overton, Laurie K

    2016-01-01

    Many types of disposable bioreactors for protein expression in insect and mammalian cells are now available. They differ in design, capacity, and sensor options, with many selections available for either rocking platform, orbitally shaken, pneumatically mixed, or stirred-tank bioreactors lined with an integral disposable bag (Shukla and Gottschalk, Trends Biotechnol 31(3):147-154, 2013). WAVE Bioreactors™ were among the first disposable systems to be developed (Singh, Cytotechnology 30:149-158, 1999). Since their commercialization in 1999, Wave Bioreactors have become routinely used in many laboratories due to their ease of operation, limited utility requirements, and protein expression levels comparability to traditional stirred-tank bioreactors. Wave Bioreactors are designed to use a presterilized Cellbag™, which is attached to a rocking platform and inflated with filtered air provided by the bioreactor unit. The Cellbag can be filled with medium and cells and maintained at a set temperature. The rocking motion, which is adjusted through angle and rock speed settings, provides mixing of oxygen (and CO2, which is used to control pH in mammalian cell cultures) from the headspace created in the inflated Cellbag with the cell culture medium and cells. This rocking motion can be adjusted to prevent cell shear damage. Dissolved oxygen and pH can be monitored during scale-up, and samples can be easily removed to monitor other parameters. Insect and mammalian cells grow very well in Wave Bioreactors (Shukla and Gottschalk, Trends Biotechnol 31(3):147-154, 2013). Combining Wave Bioreactor cell growth capabilities with recombinant baculoviruses engineered for insect or mammalian cell expression has proven to be a powerful tool for rapid production of a wide range of proteins.

  2. Moving Denitrifying Bioreactors beyond Proof of Concept: Introduction to the Special Section.

    Science.gov (United States)

    Christianson, Laura E; Schipper, Louis A

    2016-05-01

    Denitrifying bioreactors are organic carbon-filled excavations designed to enhance the natural process of denitrification for the simple, passive treatment of nitrate-nitrogen. Research on and installation of these bioreactors has accelerated within the past 10 years, particularly in watersheds concerned about high nonpoint-source nitrate loads and also for tertiary wastewater treatment. This special section, inspired by the meeting of the Managing Denitrification in Agronomic Systems Community at the 2014 Annual Meeting of the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, aims to firmly establish that denitrifying bioreactors for treatment of nitrate in drainage waters, groundwater, and some wastewaters have moved beyond the proof of concept. This collection of 14 papers expands the peer-reviewed literature of denitrifying bioreactors into new locations, applications, and environmental conditions. There is momentum behind the pairing of wood-based bioreactors with other media (biochar, corn cobs) and in novel designs (e.g., use within treatment trains or use of baffles) to broaden applicability into new kinds of waters and pollutants and to improve performance under challenging field conditions such as cool early season agricultural drainage. Concerns about negative bioreactor by-products (nitrous oxide and hydrogen sulfide emissions, start-up nutrient flushing) are ongoing, but this translates into a significant research opportunity to develop more advanced designs and to fine tune management strategies. Future research must think more broadly to address bioreactor impacts on holistic watershed health and greenhouse gas balances and to facilitate collaborations that allow investigation of mechanisms within the bioreactor "black box." PMID:27136139

  3. Moving Denitrifying Bioreactors beyond Proof of Concept: Introduction to the Special Section.

    Science.gov (United States)

    Christianson, Laura E; Schipper, Louis A

    2016-05-01

    Denitrifying bioreactors are organic carbon-filled excavations designed to enhance the natural process of denitrification for the simple, passive treatment of nitrate-nitrogen. Research on and installation of these bioreactors has accelerated within the past 10 years, particularly in watersheds concerned about high nonpoint-source nitrate loads and also for tertiary wastewater treatment. This special section, inspired by the meeting of the Managing Denitrification in Agronomic Systems Community at the 2014 Annual Meeting of the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, aims to firmly establish that denitrifying bioreactors for treatment of nitrate in drainage waters, groundwater, and some wastewaters have moved beyond the proof of concept. This collection of 14 papers expands the peer-reviewed literature of denitrifying bioreactors into new locations, applications, and environmental conditions. There is momentum behind the pairing of wood-based bioreactors with other media (biochar, corn cobs) and in novel designs (e.g., use within treatment trains or use of baffles) to broaden applicability into new kinds of waters and pollutants and to improve performance under challenging field conditions such as cool early season agricultural drainage. Concerns about negative bioreactor by-products (nitrous oxide and hydrogen sulfide emissions, start-up nutrient flushing) are ongoing, but this translates into a significant research opportunity to develop more advanced designs and to fine tune management strategies. Future research must think more broadly to address bioreactor impacts on holistic watershed health and greenhouse gas balances and to facilitate collaborations that allow investigation of mechanisms within the bioreactor "black box."

  4. RWPV bioreactor mass transport: earth-based and in microgravity

    Science.gov (United States)

    Begley, Cynthia M.; Kleis, Stanley J.

    2002-01-01

    Mass transport and mixing of perfused scalar quantities in the NASA Rotating Wall Perfused Vessel bioreactor are studied using numerical models of the flow field and scalar concentration field. Operating conditions typical of both microgravity and ground-based cell cultures are studied to determine the expected vessel performance for both flight and ground-based control experiments. Results are presented for the transport of oxygen with cell densities and consumption rates typical of colon cancer cells cultured in the RWPV. The transport and mixing characteristics are first investigated with a step change in the perfusion inlet concentration by computing the time histories of the time to exceed 10% inlet concentration. The effects of a uniform cell utilization rate are then investigated with time histories of the outlet concentration, volume average concentration, and volume fraction starved. It is found that the operating conditions used in microgravity produce results that are quite different then those for ground-based conditions. Mixing times for microgravity conditions are significantly shorter than those for ground-based operation. Increasing the differential rotation rates (microgravity) increases the mixing and transport, while increasing the mean rotation rate (ground-based) suppresses both. Increasing perfusion rates enhances mass transport for both microgravity and ground-based cases, however, for the present range of operating conditions, above 5-10 cc/min there are diminishing returns as much of the inlet fluid is transported directly to the perfusion exit. The results show that exit concentration is not a good indicator of the concentration distributions in the vessel. In microgravity conditions, the NASA RWPV bioreactor with the viscous pump has been shown to provide an environment that is well mixed. Even when operated near the theoretical minimum perfusion rates, only a small fraction of the volume provides less than the required oxygen levels

  5. Online monitoring of cartilage tissue in a novel bioreactor

    Science.gov (United States)

    von der Burg, E.; von Buttlar, M.; Grill, W.

    2011-04-01

    Standard techniques for the analysis of biological tissues like immunohistochemical staining are typically invasive and lead to mortification of cells. Non-invasive monitoring is an important element of regenerative medicine because implants and components of implants should be 100% quality-checked with non-invasive and therefore also marker-free methods. We report on a new bioreactor for the production of collagen scaffolds seeded with Mesenchymal Stem Cells (MSCs). It contains a computer controlled mechanical activation and ultrasonic online monitoring and has been constructed for the in situ determination of ultrasonic and rheological parameters. During the cultivation period of about two weeks the scaffold is periodically compressed by two movable pistons for improved differentiation of the MSCs. This periodic compression beneficially ensures the supply with nutrition even inside the sample. During the physiological stimuli, rheological properties are measured by means of highly sensitive load cells. In addition measurements of the speed of sound in the sample and in the culture medium, with frequencies up to 16 MHz, are performed continuously. Therefore piezoceramic transducers are attached to the pistons and emit and detect ultrasonic waves, travelling through the pistons, the sample and the culture medium. The time-of-flight (TOF) of the ultrasonic signals is determined in real time with the aid of chirped excitation and correlation procedures with a resolution of at least 10 ps. The implemented ultrasonic measurement scheme allows beside the speed of sound measurements the detection of the distance between the pistons with a resolution better than 100 nm. The developed monitoring delivers information on rigidity, fluid dynamics and velocity of sound in the sample and in the culture medium. The hermetically sealed bioreactor with its life support system provides a biocompatible environment for MSCs for long time cultivation.

  6. H2S removal from biogas using bioreactors: a review

    Directory of Open Access Journals (Sweden)

    E. Dumont

    2015-01-01

    Full Text Available This review aims to provide an overview of the bioprocesses used for the removal of H2S from biogas. The ability of aerobic and anoxic bioreactors (biotrickling filters, bioscrubbers, and a combination of chemical scrubbers and bioreactors to perform the degradation of H2S is considered. For each operating mode (aerobic and anoxic, the bioprocesses are presented, the operating conditions affecting performance are summarized, the state of the art of research studies is described and commercial applications are given. At laboratory-scale, whatever their operating mode, biological processes are effective for biogas cleaning and provide the same performance. The clogging of the packed bed due to the deposit of elemental sulfur S0 and biomass accumulation clearly represents the main drawback of bioprocesses. Although elimination capacities (EC determined at laboratory-scale can be very high, EC should not be higher than 90 g m-3 h-1 at industrial-scale in order to limit clogging effects. For aerobic processes, the need to control the oxygen mass transfer accurately remains a key issue for their development at full-scale. As a result, the aerobic processes alone are probably not the most suitable bioprocesses for the treatment of biogas highly loaded with H2S. For anaerobic bioprocesses using nitrate as an electron acceptor, the scale-up of the laboratory process to a full-size plant remains a challenge. However, the use of wastewater from treatment plants, which constitutes a cheap source of nitrates, represents an interesting opportunity for the development of innovative bioprocesses enabling the simultaneous removal of H2S and nitrates.

  7. Evaluation of Phytodesalination Potential of Vegetated Bioreactors Treating Greenhouse Effluent

    Directory of Open Access Journals (Sweden)

    Soheil Fatehi Pouladi

    2016-05-01

    Full Text Available The dissolved salt ions that are not absorbed during irrigation of greenhouse crops are gradually accumulated in the nutrient solution resulting in levels of salinity high enough to damage the crops. This water salinity presents operational and environmental challenges as the nutrient-rich greenhouse effluent should be discharged to the environment when deemed unsuited for irrigation. In this pilot-scale study, the potential of passive salt reduction (phytodesalination in gravel and wood-chip flow-through reactors was evaluated using seven plant species including Schoenoplectus tabernaemontani, Andropogon gerardii, Typha angustifolia, Elymus canadensis, Panicum virgatum, Spartina pectinata and Distichlis spicata along with an unplanted control reactor. While the unplanted system outperformed the planted units with gravel media, the wood-chip bioreactors with S. tabernaemontani and S. pectinata improved the greenhouse effluent reducing the solution conductivity (EC by a maximum of 15% (average = 7%. S. tabernaemontani and D. spicata showed higher accumulated contents of Na+ and Cl− in comparison with T. angustifolia and S. pectinata. Overall, S. tabernaemontani was selected as the most capable species in the wood-chip bioreactors for its better salt management via EC reduction and salt accumulation. It was however concluded that further treatment would be required for the greenhouse effluent to meet the stringent irrigation water quality guidelines in order not to pose any adverse effects on sensitive crops. Finally, the present hydraulic residence time (HRT = 3.7 days and the solution salinity concentration were identified as the potential factors that may be limiting the efficiency of plant salt uptake, emphasizing the need for conducting more research on the optimization and enhancement of passive desalination systems for the greenhouse effluent.

  8. Non-disruptive measurement system of cell viability in bioreactors

    Science.gov (United States)

    Rudek, F.; Nelsen, B. L.; Baselt, T.; Berger, T.; Wiele, M.; Prade, I.; Hartmann, P.

    2016-04-01

    Nutrient and oxygen transport, as well as the removal of metabolic waste are essential processes to support and maintain viable tissue. Current bioreactor technology used to grow tissue cultures in vitro has a fundamental limit to the thickness of tissues. Based on the low diffusion limit of oxygen a maximum tissue thickness of 200 μm is possible. The efficiency of those systems is currently under investigation. During the cultivation process of the artificial tissue in bioreactors, which lasts 28 days or longer, there are no possibilities to investigate the viability of cells. This work is designed to determine the influence of a non-disruptive cell viability measuring system on cellular activity. The measuring system uses a natural cellular marker produced during normal metabolic activity. Nicotinamide adenine dinucleotide (NADH) is a coenzyme naturally consumed and produced during cellular metabolic processes and has thoroughly been studied to determine the metabolic state of a cell. Measuring the fluorescence of NADH within the cell represents a non-disruptive marker for cell viability. Since the measurement process is optical in nature, NADH fluorescence also provides a pathway for sampling at different measurement depths within a given tissue sample. The measurement system we are using utilizes a special UV light source, to excite the NADH fluorescence state. However, the high energy potentially alters or harms the cells. To investigate the influence of the excitation signal, the cells were irradiated with a laser operating at a wavelength of 355 nm and examined for cytotoxic effects. The aim of this study was to develop a non-cytotoxic system that is applicable for large-scale operations during drug-tissue interaction testing.

  9. Allergénicité des Granules Cytoplasmiques de Pollen

    OpenAIRE

    Abou Chakra, Oussama

    2009-01-01

    Le pollen des Graminées est l'un des principaux vecteurs d'allergènes. Il contribue à l'apparition des allergies respiratoires comme l'asthme et la rhinite allergique. En contact avec l'eau de pluie ou des polluants atmosphériques, le pollen peut libérer des microparticules (

  10. Oxygen mass transfer and scale-up studies in baffled roller bioreactors.

    Science.gov (United States)

    Nikakhtari, H; Song, W; Nemati, M; Hill, G A

    2014-02-01

    Oxygen mass transfer was studied in conventional, bead mill and baffled roller bioreactors. Using central composite rotational design, impacts of size, rotation speed and working volume on the oxygen mass transfer were evaluated. Baffled roller bioreactor outperformed its conventional and bead mill counterparts, with the highest k(L)a obtained in these configurations being 0.58, 0.19, 0.41 min(-1), respectively. Performances of the bead mill and baffled roller bioreactor were only comparable when a high bead loading (40%) was applied. Regardless of configuration increase in rotation speed and decrease in working volume improved the oxygen mass transfer rate. Increase in size led to enhanced mass transfer and higher k(L)a in baffled roller bioreactor (0.49 min(-1) for 2.2 L and 1.31 min(-1) for 55 L bioreactors). Finally, the experimentally determined k(L)a in the baffled roller bioreactors of different sizes fit reasonably well to an empirical correlation describing the k(L)a in terms of dimensionless numbers.

  11. Intelligent Bioreactor Management Information System (IBM-IS) for Mitigation of Greenhouse Gas Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Paul Imhoff; Ramin Yazdani; Don Augenstein; Harold Bentley; Pei Chiu

    2010-04-30

    Methane is an important contributor to global warming with a total climate forcing estimated to be close to 20% that of carbon dioxide (CO2) over the past two decades. The largest anthropogenic source of methane in the US is 'conventional' landfills, which account for over 30% of anthropogenic emissions. While controlling greenhouse gas emissions must necessarily focus on large CO2 sources, attention to reducing CH4 emissions from landfills can result in significant reductions in greenhouse gas emissions at low cost. For example, the use of 'controlled' or bioreactor landfilling has been estimated to reduce annual US greenhouse emissions by about 15-30 million tons of CO2 carbon (equivalent) at costs between $3-13/ton carbon. In this project we developed or advanced new management approaches, landfill designs, and landfill operating procedures for bioreactor landfills. These advances are needed to address lingering concerns about bioreactor landfills (e.g., efficient collection of increased CH4 generation) in the waste management industry, concerns that hamper bioreactor implementation and the consequent reductions in CH4 emissions. Collectively, the advances described in this report should result in better control of bioreactor landfills and reductions in CH4 emissions. Several advances are important components of an Intelligent Bioreactor Management Information System (IBM-IS).

  12. Biodegradation of High Concentrations of Benzene Vapors in a Two Phase Partition Stirred Tank Bioreactor

    Directory of Open Access Journals (Sweden)

    Ali Karimi

    2013-01-01

    Full Text Available The present study examined the biodegradation rate of benzene vapors in a two phase stirred tank bioreactor by a bacterial consortium obtained from wastewater of an oil industry refinery house. Initially, the ability of the microbial consortium for degrading benzene was evaluated before running the bioreactor. The gaseous samples from inlet and outlet of bioreactor were directly injected into a gas chromatograph to determine benzene concentrations. Carbone oxide concentration at the inlet and outlet of bioreactor were also measured with a CO2 meter to determine the mineralization rate of benzene. Influence of the second non-aqueous phase (silicon oil has been emphasized, so at the first stage the removal efficiency (RE and elimination capacity (EC of benzene vapors were evaluated without any organic phase and in the second stage, 10% of silicon oil was added to bioreactor media as an organic phase. Addition of silicon oil increased the biodegradation performance up to an inlet loading of 5580?mg/m3, a condition at which, the elimination capacity and removal efficiency were 181?g/m3/h and 95% respectively. The elimination rate of benzene increased by 38% in the presence of 10% of silicone oil. The finding of this study demonstrated that two phase partition bioreactors (TPPBs are potentially effective tools for the treatment of gas streams contaminated with high concentrations of poorly water soluble organic contaminant, such as benzene.

  13. Biodegradation of high concentrations of benzene vapors in a two phase partition stirred tank bioreactor

    Directory of Open Access Journals (Sweden)

    Karimi Ali

    2013-01-01

    Full Text Available Abstract The present study examined the biodegradation rate of benzene vapors in a two phase stirred tank bioreactor by a bacterial consortium obtained from wastewater of an oil industry refinery house. Initially, the ability of the microbial consortium for degrading benzene was evaluated before running the bioreactor. The gaseous samples from inlet and outlet of bioreactor were directly injected into a gas chromatograph to determine benzene concentrations. Carbone oxide concentration at the inlet and outlet of bioreactor were also measured with a CO2 meter to determine the mineralization rate of benzene. Influence of the second non-aqueous phase (silicon oil has been emphasized, so at the first stage the removal efficiency (RE and elimination capacity (EC of benzene vapors were evaluated without any organic phase and in the second stage, 10% of silicon oil was added to bioreactor media as an organic phase. Addition of silicon oil increased the biodegradation performance up to an inlet loading of 5580 mg/m3, a condition at which, the elimination capacity and removal efficiency were 181 g/m3/h and 95% respectively. The elimination rate of benzene increased by 38% in the presence of 10% of silicone oil. The finding of this study demonstrated that two phase partition bioreactors (TPPBs are potentially effective tools for the treatment of gas streams contaminated with high concentrations of poorly water soluble organic contaminant, such as benzene.

  14. A comparative study of leachate quality and biogas generation in simulated anaerobic and hybrid bioreactors.

    Science.gov (United States)

    Xu, Qiyong; Tian, Ying; Wang, Shen; Ko, Jae Hac

    2015-07-01

    Research has been conducted to compare leachate characterization and biogas generation in simulated anaerobic and hybrid bioreactor landfills with typical Chinese municipal solid waste (MSW). Three laboratory-scale reactors, an anaerobic (A1) and two hybrid bioreactors (C1 and C2), were constructed and operated for about 10months. The hybrid bioreactors were operated in an aerobic-anaerobic mode with different aeration frequencies by providing air into the upper layer of waste. Results showed that the temporary aeration into the upper layer aided methane generation by shortening the initial acidogenic phase because of volatile fatty acids (VFAs) reduction and pH increase. Chemical oxygen demand (COD) decreased faster in the hybrid bioreactors, but the concentrations of ammonia-nitrogen in the hybrid bioreactors were greater than those in the anaerobic control. Methanogenic conditions were established within 75d and 60d in C1 and C2, respectively. However, high aeration frequency led to the consumption of organic matters by aerobic degradation and resulted in reducing accumulative methane volume. The temporary aeration enhanced waste settlement and the settlement increased with increasing the frequency of aeration. Methane production was inhibited in the anaerobic control; however, the total methane generations from hybrid bioreactors were 133.4L/kgvs and 113.2L/kgvs. As for MSW with high content of food waste, leachate recirculation right after aeration stopped was not recommended due to VFA inhibition for methanogens. PMID:25857421

  15. A comparative study of leachate quality and biogas generation in simulated anaerobic and hybrid bioreactors.

    Science.gov (United States)

    Xu, Qiyong; Tian, Ying; Wang, Shen; Ko, Jae Hac

    2015-07-01

    Research has been conducted to compare leachate characterization and biogas generation in simulated anaerobic and hybrid bioreactor landfills with typical Chinese municipal solid waste (MSW). Three laboratory-scale reactors, an anaerobic (A1) and two hybrid bioreactors (C1 and C2), were constructed and operated for about 10months. The hybrid bioreactors were operated in an aerobic-anaerobic mode with different aeration frequencies by providing air into the upper layer of waste. Results showed that the temporary aeration into the upper layer aided methane generation by shortening the initial acidogenic phase because of volatile fatty acids (VFAs) reduction and pH increase. Chemical oxygen demand (COD) decreased faster in the hybrid bioreactors, but the concentrations of ammonia-nitrogen in the hybrid bioreactors were greater than those in the anaerobic control. Methanogenic conditions were established within 75d and 60d in C1 and C2, respectively. However, high aeration frequency led to the consumption of organic matters by aerobic degradation and resulted in reducing accumulative methane volume. The temporary aeration enhanced waste settlement and the settlement increased with increasing the frequency of aeration. Methane production was inhibited in the anaerobic control; however, the total methane generations from hybrid bioreactors were 133.4L/kgvs and 113.2L/kgvs. As for MSW with high content of food waste, leachate recirculation right after aeration stopped was not recommended due to VFA inhibition for methanogens.

  16. Verification of energy dissipation rate scalability in pilot and production scale bioreactors using computational fluid dynamics.

    Science.gov (United States)

    Johnson, Chris; Natarajan, Venkatesh; Antoniou, Chris

    2014-01-01

    Suspension mammalian cell cultures in aerated stirred tank bioreactors are widely used in the production of monoclonal antibodies. Given that production scale cell culture operations are typically performed in very large bioreactors (≥ 10,000 L), bioreactor scale-down and scale-up become crucial in the development of robust cell-culture processes. For successful scale-up and scale-down of cell culture operations, it is important to understand the scale-dependence of the distribution of the energy dissipation rates in a bioreactor. Computational fluid dynamics (CFD) simulations can provide an additional layer of depth to bioreactor scalability analysis. In this communication, we use CFD analyses of five bioreactor configurations to evaluate energy dissipation rates and Kolmogorov length scale distributions at various scales. The results show that hydrodynamic scalability is achievable as long as major design features (# of baffles, impellers) remain consistent across the scales. Finally, in all configurations, the mean Kolmogorov length scale is substantially higher than the average cell size, indicating that catastrophic cell damage due to mechanical agitation is highly unlikely at all scales.

  17. Application of wireless sensor network based on ZigBee technology in photo-bioreactors system

    Science.gov (United States)

    Liu, Bo; Chen, Ming; Chi, Tao

    2013-03-01

    A photo-bioreactor is a bioreactor that incorporates some types of light source to provide photonic energy input into the reactor[1][2]. In the situation of Large-scale industrialization production of micro-algae, hundreds of photo-bioreactors will be deployed in a factory, thus the design of entire system is based on the distribution theory and the remote monitoring must be deployed. So the communication in the entire photo-bioreactors system is very important. However, the recent solution of communication is based on RS-485 data bus, and the twisted-pair cable is used as the communication medium, so the flexibility and scalability of entire system reduce. In this paper, the wireless sensor network (WSN) based on ZigBee technology is applied to this photo-bioreactors system, and the related key problems include the architecture of entire system and the design of wireless sensor network nodes[3]~[6]. The application of this technology will also reduce the cost and effectively raise the intelligence level of the large-scale industrialization photo-bioreactors system.

  18. Nitrogen removal through different pathways in an aged refuse bioreactor treating mature landfill leachate.

    Science.gov (United States)

    Xie, Bing; Lv, Zhuo; Hu, Chong; Yang, Xuezhi; Li, Xiangzhen

    2013-10-01

    In this study, an aged refuse bioreactor was constructed to remove nitrogen in a mature landfill leachate. The nitrogen removal efficiency and the microbial community composition in the bioreactor were investigated. The results showed that the aged refuse bioreactor removed more than 90 % of total nitrogen in the leachate under the nitrogen loading rate (NLR) of 0.74 g/kg (vs) day, and the total nitrogen removal rate decreased to 62.2 % when NLR increased up to 2.03 g/kg (vs) day. Quantitative polymerase chain reaction results showed that the average cell number of ammonia-oxidizing bacteria in the bioreactor was 1.58 × 10(8) cells/g, which accounted for 0.41 % of total bacteria. The number of anammox bacteria in the reactor was 1.09 × 10(8) cells/g, which accounted for 0.27 % of total bacteria. Isotopic (15)N tracing experiments showed that nearly 10 % of nitrogen was removed by anammox. High-throughout 454 pyrosequencing revealed that the predominant bacteria in the bioreactor were Proteobacteria, Chloroflexi, Actinobacteria, Bacteroidetes, and Gemmatimonadetes, including various nitrifiers and denitrifiers with diverse heterotrophic and autotrophic metabolic pathways, supporting that nitrogen was removed through different pathways in this aged refuse bioreactor.

  19. Characterization of algal and microbial community growth in a wastewater treating batch photo-bioreactor inoculated with lake water

    OpenAIRE

    Krustok, Ivo; Odlare, Monica; M.A., Shabiimam; Truu, Jaak; Truu, Marika; Ligi, Teele; Nehrenheim, Emma

    2015-01-01

    Microalgae grown in photo-bioreactors can be a valuable source of biomass, especially when combined with wastewater treatment. While most published research has studied pure cultures, the consortia of algae and bacteria from wastewater have more complex community dynamics which affect both the biomass production and pollutant removal. In this paper we investigate the dynamics of algal and bacterial growth in wastewater treating batch photo-bioreactors. The photo-bioreactors were inoculated wi...

  20. Treatment of cattle-slaughterhouse wastewater and the reuse of sludge for biodiesel production by microalgal heterotrophic bioreactors

    OpenAIRE

    Mariana Manzoni Maroneze; Juliano Smanioto Barin; Cristiano Ragagnin de Menezes; Maria Isabel Queiroz; Leila Queiroz Zepka; Eduardo Jacob-Lopes

    2014-01-01

    Microalgal heterotrophic bioreactors are a potential technological development that can convert organic matter, nitrogen and phosphorus of wastewaters into a biomass suitable for energy production. The aim of this work was to evaluate the performance of microalgal heterotrophic bioreactors in the secondary treatment of cattle-slaughterhouse wastewater and the reuse of microalgal sludge for biodiesel production. The experiments were performed in a bubble column bioreactor using the microalgae ...

  1. Fiber Attachment Module Experiment (FAME): Using a Multiplexed Miniature Hollow Fiber Membrane Bioreactor Solution for Rapid Process Testing

    Science.gov (United States)

    Coutts, Janelle L.; Lunn, Griffin M.; Koss, Lawrence L.; Hummerick, Mary E.; Spencer, Lachelle E.; Johnsey, Marissa N.; Richards, Jeffrey T.; Ellis, Ronald; Birmele, Michele N.; Wheeler, Raymond M.

    2014-01-01

    Bioreactor research is mostly limited to continuous stirred-tank reactors (CSTRs) which are not an option for microgravity (g) applications due to the lack of a gravity gradient to drive aeration as described by the Archimedes principle. Bioreactors and filtration systems for treating wastewater in g could avoid the need for harsh pretreatment chemicals and improve overall water recovery. Solution: Membrane Aerated Bioreactors (MABRs) for g applications, including possible use for wastewater treatment systems for the International Space Station (ISS).

  2. Evaluation of the Growth Environment of a Hydrostatic Force Bioreactor for Preconditioning of Tissue-Engineered Constructs

    OpenAIRE

    Reinwald, Yvonne; Leonard, Katherine H.L.; Henstock, James R.; Whiteley, Jonathan P.; Osborne, James M.; Waters, Sarah L.; Levesque, Philippe; El Haj, Alicia J.

    2014-01-01

    Bioreactors have been widely acknowledged as valuable tools to provide a growth environment for engineering tissues and to investigate the effect of physical forces on cells and cell-scaffold constructs. However, evaluation of the bioreactor environment during culture is critical to defining outcomes. In this study, the performance of a hydrostatic force bioreactor was examined by experimental measurements of changes in dissolved oxygen (O2), carbon dioxide (CO2), and pH after mechanical stim...

  3. La territorialisation des politiques environnementales

    Directory of Open Access Journals (Sweden)

    Amédée Mollard

    2010-10-01

    Full Text Available Le point de départ de cet article est la grande variabilité de la pollution nitrique diffuse de l’eau due à l’agriculture. Celle-ci dépend en particulier du climat, des types de sol et des systèmes de production agricole. Nos recherches réalisées de façon interdisciplinaire à partir de deux sites différents en France, montrent que cette hétérogénéité spatio-temporelle conditionne les pratiques agricoles mises en œuvre pour réduire la pollution au niveau de la norme admise. De ce fait, les pratiques les plus « coût-efficaces » diffèrent d’un territoire à l’autre, en fonction des caractéristiques locales. Ces résultats mettent donc en évidence une efficacité potentielle d’une territorialisation des politiques publiques. En théorie, de telles politiques sont considérées comme optimales par les économistes, car elles incitent les agents à moduler leurs efforts en fonction de la sensibilité du milieu. Mais, selon les études empiriques, cet avantage serait annulé par un coût élevé de mise en œuvre, de contrôle et de surveillance. Pour maintenir leur avantage sur des politiques uniformes, les politiques territorialisées devraient être mises en œuvre à un niveau spatial optimal. Un tel niveau devrait au minimum atteindre un compromis entre l’économie réalisée grâce à une modulation adaptée aux conditions locales et les sur-coûts dus à la décentralisation des solutions mises en œuvre. Cet article analyse la pertinence d’une prise en compte de ces spécificités par des politiques territorialisées. L’efficacité d’une régulation différenciée de la pollution nitrique est étudiée ici en évaluant l’importance de la variabilité spatiale des paramètres physiques et des coûts de la territorialisation.The paper starts with the wide variability of nonpoint water nitrogenous pollution generated by agriculture. This variability depends especially on climate, soil types and farming

  4. Géographie des interfaces. Une nouvelle vision des territoires

    Directory of Open Access Journals (Sweden)

    Marie Redon

    2011-07-01

    Full Text Available Littéralement, une interface est une surface de séparation entre deux états distincts de la matière. Le terme, ayant cheminé de la physique à la biologie, et aussi désormais d’usage répandu en informatique. En géographie, l’usage du mot s’est développé dans les années 1980 et peut être défini comme un espace permettant la mise en relation de deux espaces/territoires différents, influencé par des échanges entre l’un et l’autre, et se distinguant par là-même des deux espaces contigus. Intégrant...

  5. N₂O emission from a combined ex-situ nitrification and in-situ denitrification bioreactor landfill.

    Science.gov (United States)

    Wang, Ya-nan; Sun, Ying-jie; Wang, Lei; Sun, Xiao-jie; Wu, Hao; Bian, Rong-xing; Li, Jing-jing

    2014-11-01

    A combined process comprised of ex-situ nitrification in an aged refuse bioreactor (designated as A bioreactor) and in-situ denitrification in a fresh refuse bioreactor (designated as F bioreactor) was constructed for investigating N2O emission during the stabilization of municipal solid waste (MSW). The results showed that N2O concentration in the F bioreactor varied from undetectable to about 130 ppm, while it was much higher in the A bioreactor with the concentration varying from undetectable to about 900 ppm. The greatly differences of continuous monitoring of N2O emission after leachate cross recirculation in each period were primarily attributed to the stabilization degree of MSW. Moreover, the variation of N2O concentration was closely related to the leachate quality in both bioreactors and it was mainly affected by the COD and COD/TN ratio of leachate from the F bioreactor, as well as the DO, ORP, and NO3(-)-N of leachate from the A bioreactor.

  6. Evaluation of a new mist-chamber bioreactor for biotechnological applications.

    Science.gov (United States)

    Tscheschke, Bernd; Dreimann, Janis; von der Ruhr, Jürgen W; Schmidt, Timo; Stahl, Frank; Just, Lothar; Scheper, Thomas

    2015-06-01

    In this article we describe the development, the characterization and the evaluation of a novel bioreactor type for the cultivation of different pro- and eukaryotic cell-systems: the mist-chamber bioreactor. This innovative bioreactor meets the demand of cultivation systems for shear stress sensitive cells with high requirements for gas supply. Within the mist-chamber bioreactor the cells are cultivated inside an aerosol of vaporized medium generated by ultrasonic vaporization. In contrast to many established bioreactor systems the mist-chamber bioreactor offers an environment with an excellent gas supply without any impeller or gas bubble induced shear stress. A mist-chamber bioreactor prototype has been manufactured and characterized during this work. In the technical and chemical characterization we evaluated the vaporization process, resulting in a vaporization performance of 32 mL/h at working conditions. On this basis we calculated a biomass of 1.4 g (S. cerevisiae, qs  = 3.45 × 10-3 mol/g/h) and 3.4 g (Aspergillus niger, qs  = 1.33 × 10-3 mol/g/h) where the growth rate becomes limited by transport processes. Additionally, we determined a homogenous cultivation area to a height of 3 cm giving a total volume of 0.45 L for the cultivation. Medium components were examined according to their stability during vaporization with the result that all components are stable for at least 5 days. After the technical characterization we demonstrated the feasibility to cultivate S. cerevisiae and F. velupites in the mist-chamber bioreactor. The results demonstrated that the mist-chamber bioreactor is able to transport a sufficient amount of nutrients consistently to the cell samples and offers an excellent oxygen supply without any shear stress inducing aeration. Furthermore we successfully cultivated F. velupites in a solid state cultivation in a long term experiment. The data indicate that the new bioreactor concept can contribute to

  7. Evaluation of a new mist-chamber bioreactor for biotechnological applications.

    Science.gov (United States)

    Tscheschke, Bernd; Dreimann, Janis; von der Ruhr, Jürgen W; Schmidt, Timo; Stahl, Frank; Just, Lothar; Scheper, Thomas

    2015-06-01

    In this article we describe the development, the characterization and the evaluation of a novel bioreactor type for the cultivation of different pro- and eukaryotic cell-systems: the mist-chamber bioreactor. This innovative bioreactor meets the demand of cultivation systems for shear stress sensitive cells with high requirements for gas supply. Within the mist-chamber bioreactor the cells are cultivated inside an aerosol of vaporized medium generated by ultrasonic vaporization. In contrast to many established bioreactor systems the mist-chamber bioreactor offers an environment with an excellent gas supply without any impeller or gas bubble induced shear stress. A mist-chamber bioreactor prototype has been manufactured and characterized during this work. In the technical and chemical characterization we evaluated the vaporization process, resulting in a vaporization performance of 32 mL/h at working conditions. On this basis we calculated a biomass of 1.4 g (S. cerevisiae, qs  = 3.45 × 10-3 mol/g/h) and 3.4 g (Aspergillus niger, qs  = 1.33 × 10-3 mol/g/h) where the growth rate becomes limited by transport processes. Additionally, we determined a homogenous cultivation area to a height of 3 cm giving a total volume of 0.45 L for the cultivation. Medium components were examined according to their stability during vaporization with the result that all components are stable for at least 5 days. After the technical characterization we demonstrated the feasibility to cultivate S. cerevisiae and F. velupites in the mist-chamber bioreactor. The results demonstrated that the mist-chamber bioreactor is able to transport a sufficient amount of nutrients consistently to the cell samples and offers an excellent oxygen supply without any shear stress inducing aeration. Furthermore we successfully cultivated F. velupites in a solid state cultivation in a long term experiment. The data indicate that the new bioreactor concept can contribute to

  8. Contribution au catalogue des lichens et des champignons lichénicoles du Parc National des Cévennes

    OpenAIRE

    Coste, Clother

    2011-01-01

    International audience De récentes prospections lichénologiques effectuées dans le Parc National des Cévennes ont permis de compléter le catalogue des lichens, des champignons lichénicoles et des acomycètes du Parc. Ainsi ont été observées : 1 espèce nouvellement trouvée en France (Arthopyrenia subcerasi (Vain.) Zahlbr.) ; 16 espèces non encore signalées dans le Parc national (Bacidia subacerina Vain., Caloplaca cerinoides (Anzi) Jatta, Caloplaca haematites (Chaub. ex St.- Amans) Zwackh, C...

  9. Diagnostic des capteurs pour la commande des entrainements électriques

    OpenAIRE

    Diao, Sidath; Diallo, Demba; MAKNI, Zaatar; Marchand, Claude

    2014-01-01

    Ce papier traite de la détection des défauts sur les capteurs pour un ensemble Machine Synchrone et Onduleur par des méthodes d'estimation d'état. Les capteurs à surveiller dans notre cas sont ceux de la position/vitesse et des courants de phase. Des résultats expérimentaux illustrent l'approche utilisée.

  10. Croissance des jeunes entreprises et territoires

    OpenAIRE

    Philippe Moati; Marjorie Mazars; Laurent Pouquet

    2006-01-01

    Cette étude s’intéresse à l’influence des caractéristiques du territoire d’implantation sur la croissance des jeunes entreprises. Le territoire constitue à la fois pour les entreprises une offre de ressources, des débouchés et un accès à des mécanismes de coordination. Par la mobilisation des données individuelles de l’enquêtes SINE de l’INSEE, un modèle de croissance est construit afin de tester l’influence d’un large ensemble de variables décrivant l’environnement local des entreprises. Il ...

  11. Optimisation des plannings des affectations multi niveaux des flux des céréales importées

    OpenAIRE

    Mkaouar, Houssemeddine; Mesghouni, Khaled

    2009-01-01

    International audience Dans cet article on s'intéresse aux problèmes de prise de décision dans le domaine de la distribution des céréales en Tunisie notamment ceux relatifs à la planification et à l'affectation multi niveaux des céréales importés. L'objectif est d'optimiser la gestion d'une entité de la chaîne logistique céréalière depuis l'approvisionnement (importation) jusqu'à la vente aux clients (minoteries, semouleries,...) en passant par trois niveaux d'affectation. A cet effet on a...

  12. Des paysans dans la jungle

    OpenAIRE

    Krauskopff, Gisèle

    2003-01-01

    Cet article décrit les techniques de piégeage au filet utilisées par les Tharu. paysans qui vivent dans la forêt paludéenne du Terai. La chasse, comme la pêche, se pratique sans effusion de sang. Lorsqu'ils s'adressent aux esprits de la malemort, responsables de la plupart des maladies, les prêtres utilisent des techniques rituelles différentes selon la « catégorie du paysage » à laquelle les esprits sont associés, site habité ou forêt. « Dans la forêt », le prêtre, installé sur ses ma...

  13. Eis und die Entstehung des Lebens

    OpenAIRE

    Trinks, Hauke; Schröder, Wolfgang; Biebricher, Christof K.

    2003-01-01

    Mannigfaltige Umgebungen wurden bisher als Ort für die Entstehung des Lebens vorgeschlagen. Ausgehend von den Ergebnissen in der Arktis durchgeführter Experimente eines der Autoren sowie weiteren Hinweisen zu besonderen Eigenschaften des arktischen Meereis in der Literatur, schlagen wir vor, dass eine für den Ursprung des Lebens bislang weitgehend unbeachtete Umgebung, nämlich das Meerwassereis der Polkappen, ausgezeichnete Bedingungen für die Entwicklung der allerfrühesten genetischen Elemen...

  14. Catalogue ostéologique des oiseaux

    NARCIS (Netherlands)

    Oort, van E.D.

    1907-01-01

    Je le crois utile de faire précéder le présent Catalogue par quelques remarques. J’ai énuméré autant que possible les parties, qui font défaut aux squelettes. L’absence de plusieurs osselets, comme des doigts, des vertèbres caudales, des côtes etc. au même échantillon, est indiqué par „incomplet” ou

  15. Mead und das Problem des gemeinsamen Wissens

    OpenAIRE

    Haferkamp, Hans

    1985-01-01

    Ausgangspunkt des Artikels ist die Handlungsrelevanz sozialer Vorstellungen. Verbreitete Konzeptualisierungen dieser Vorstellungen sind nicht zufriedenstellend. In Abschnitt 2 wird die dimensionale Analyse des Konzepts 'gemeinsames Wissen' durchgeführt, und in Abschnitt 3 werden Probleme und Perspektiven der Erklärung der Entstehung dieses Wissens analysiert. Sowohl für die Entwicklung des Konzepts wie der erklärungskräftigen Thesen erfolgt ein Rückgriff auf Mead. Eine Reihe seiner Ide...

  16. Manuel des chefs de mission des CNO: Rio 2016 : avril 2016

    OpenAIRE

    2016-01-01

    Publié en avril 2016, ce « Manuel des chefs de mission » donne un aperçu détaillé des services offerts aux Comités Nationaux Olympiques (CNO) pendant les Jeux Olympiques Rio 2016, ainsi que des opérations pendant les Jeux.

  17. Salon suisse des beaux-arts et des arts décoratifs

    OpenAIRE

    Serment, William

    2015-01-01

    Critique très mitigée des deux tableaux exposés au Salon suisse des beaux-arts et des arts décoratifs. Critique signée W. Serment. Apprécie la vigueur du dessin mais pas la manière de traiter le sujet.

  18. Zur Struktur des deutschen Schriftsystems

    OpenAIRE

    Rezec, Oliver

    2009-01-01

    Die vorliegende Arbeit will ein differenziertes und konsistentes Strukturmodell des deutschen Schriftsystems entwickeln. Noch immer fußt die Schriftlinguistik auf unsoliden theoretischen Grundlagen: So sind für das Graphem zwei verschiedene, einander widersprechende Definitionen in Gebrauch, die oft sogar miteinander vermischt werden. Zudem erschöpft sich die Graphematik, reduziert auf die Rolle einer Hilfswissenschaft der Orthographie, traditionell in der Betrachtung von Graphem-Phonem-Korre...

  19. Biofabrication of customized bone grafts by combination of additive manufacturing and bioreactor knowhow

    International Nuclear Information System (INIS)

    This study reports on an original concept of additive manufacturing for the fabrication of tissue engineered constructs (TEC), offering the possibility of concomitantly manufacturing a customized scaffold and a bioreactor chamber to any size and shape. As a proof of concept towards the development of anatomically relevant TECs, this concept was utilized for the design and fabrication of a highly porous sheep tibia scaffold around which a bioreactor chamber of similar shape was simultaneously built. The morphology of the bioreactor/scaffold device was investigated by micro-computed tomography and scanning electron microscopy confirming the porous architecture of the sheep tibiae as opposed to the non-porous nature of the bioreactor chamber. Additionally, this study demonstrates that both the shape, as well as the inner architecture of the device can significantly impact the perfusion of fluid within the scaffold architecture. Indeed, fluid flow modelling revealed that this was of significant importance for controlling the nutrition flow pattern within the scaffold and the bioreactor chamber, avoiding the formation of stagnant flow regions detrimental for in vitro tissue development. The bioreactor/scaffold device was dynamically seeded with human primary osteoblasts and cultured under bi-directional perfusion for two and six weeks. Primary human osteoblasts were observed homogenously distributed throughout the scaffold, and were viable for the six week culture period. This work demonstrates a novel application for additive manufacturing in the development of scaffolds and bioreactors. Given the intrinsic flexibility of the additive manufacturing technology platform developed, more complex culture systems can be fabricated which would contribute to the advances in customized and patient-specific tissue engineering strategies for a wide range of applications. (paper)

  20. Analysis of drug metabolism activities in a miniaturized liver cell bioreactor for use in pharmacological studies.

    Science.gov (United States)

    Hoffmann, Stefan A; Müller-Vieira, Ursula; Biemel, Klaus; Knobeloch, Daniel; Heydel, Sandra; Lübberstedt, Marc; Nüssler, Andreas K; Andersson, Tommy B; Gerlach, Jörg C; Zeilinger, Katrin

    2012-12-01

    Based on a hollow fiber perfusion technology with internal oxygenation, a miniaturized bioreactor with a volume of 0.5 mL for in vitro studies was recently developed. Here, the suitability of this novel culture system for pharmacological studies was investigated, focusing on the model drug diclofenac. Primary human liver cells were cultivated in bioreactors and in conventional monolayer cultures in parallel over 10 days. From day 3 on, diclofenac was continuously applied at a therapeutic concentration (6.4 µM) for analysis of its metabolism. In addition, the activity and gene expression of the cytochrome P450 (CYP) isoforms CYP1A2, CYP2B6, CYP2C9, CYP2D6, and CYP3A4 were assessed. Diclofenac was metabolized in bioreactor cultures with an initial conversion rate of 230 ± 57 pmol/h/10(6) cells followed by a period of stable conversion of about 100 pmol/h/10(6) cells. All CYP activities tested were maintained until day 10 of bioreactor culture. The expression of corresponding mRNAs correlated well with the degree of preservation. Immunohistochemical characterization showed the formation of neo-tissue with expression of CYP2C9 and CYP3A4 and the drug transporters breast cancer resistance protein (BCRP) and multidrug resistance protein 2 (MRP2) in the bioreactor. In contrast, monolayer cultures showed a rapid decline of diclofenac conversion and cells had largely lost activity and mRNA expression of the assessed CYP isoforms at the end of the culture period. In conclusion, diclofenac metabolism, CYP activities and gene expression levels were considerably more stable in bioreactor cultures, making the novel bioreactor a useful tool for pharmacological or toxicological investigations requiring a highly physiological in vitro representation of the liver.

  1. A New Fluidized Bed Bioreactor Based on Diversion-Type Microcapsule Suspension for Bioartificial Liver Systems.

    Science.gov (United States)

    Lu, Juan; Zhang, Xiaoqian; Li, Jianzhou; Yu, Liang; Chen, Ermei; Zhu, Danhua; Zhang, Yimin; Li, LanJuan

    2016-01-01

    A fluidized bed bioreactor containing encapsulated hepatocytes may be a valuable alternative to a hollow fiber bioreactor for achieving the improved mass transfer and scale-up potential necessary for clinical use. However, a conventional fluidized bed bioreactor (FBB) operating under high perfusion velocity is incapable of providing the desired performance due to the resulting damage to cell-containing microcapsules and large void volume. In this study, we developed a novel diversion-type microcapsule-suspension fluidized bed bioreactor (DMFBB). The void volume in the bioreactor and stability of alginate/chitosan microcapsules were investigated under different flow rates. Cell viability, synthesis and metabolism functions, and expression of metabolizing enzymes at transcriptional levels in an encapsulated hepatocyte line (C3A cells) were determined. The void volume was significantly less in the novel bioreactor than in the conventional FBB. In addition, the microcapsules were less damaged in the DMFBB during the fluidization process as reflected by the results for microcapsule retention rates, swelling, and breakage. Encapsulated C3A cells exhibited greater viability and CYP1A2 and CYP3A4 activity in the DMFBB than in the FBB, although the increases in albumin and urea synthesis were less prominent. The transcription levels of several CYP450-related genes and an albumin-related gene were dramatically greater in cells in the DMFBB than in those in the FBB. Taken together, our results suggest that the DMFBB is a promising alternative for the design of a bioartificial liver system based on a fluidized bed bioreactor with encapsulated hepatocytes for treating patients with acute hepatic failure or other severe liver diseases.

  2. Biofabrication of customized bone grafts by combination of additive manufacturing and bioreactor knowhow.

    Science.gov (United States)

    Costa, Pedro F; Vaquette, Cédryck; Baldwin, Jeremy; Chhaya, Mohit; Gomes, Manuela E; Reis, Rui L; Theodoropoulos, Christina; Hutmacher, Dietmar W

    2014-09-01

    This study reports on an original concept of additive manufacturing for the fabrication of tissue engineered constructs (TEC), offering the possibility of concomitantly manufacturing a customized scaffold and a bioreactor chamber to any size and shape. As a proof of concept towards the development of anatomically relevant TECs, this concept was utilized for the design and fabrication of a highly porous sheep tibia scaffold around which a bioreactor chamber of similar shape was simultaneously built. The morphology of the bioreactor/scaffold device was investigated by micro-computed tomography and scanning electron microscopy confirming the porous architecture of the sheep tibiae as opposed to the non-porous nature of the bioreactor chamber. Additionally, this study demonstrates that both the shape, as well as the inner architecture of the device can significantly impact the perfusion of fluid within the scaffold architecture. Indeed, fluid flow modelling revealed that this was of significant importance for controlling the nutrition flow pattern within the scaffold and the bioreactor chamber, avoiding the formation of stagnant flow regions detrimental for in vitro tissue development. The bioreactor/scaffold device was dynamically seeded with human primary osteoblasts and cultured under bi-directional perfusion for two and six weeks. Primary human osteoblasts were observed homogenously distributed throughout the scaffold, and were viable for the six week culture period. This work demonstrates a novel application for additive manufacturing in the development of scaffolds and bioreactors. Given the intrinsic flexibility of the additive manufacturing technology platform developed, more complex culture systems can be fabricated which would contribute to the advances in customized and patient-specific tissue engineering strategies for a wide range of applications.

  3. On-line removal of volatile fatty acids from CELSS anaerobic bioreactor via nanofiltration

    Science.gov (United States)

    Colon, Guillermo

    1995-01-01

    The CELSS (controlled ecological life support system) resource recovery system, which is a waste processing system, uses aerobic and anaerobic bioreactors to recover plants nutrients and secondary foods from the inedible biomass. The anaerobic degradation of the inedible biomass by means of culture of rumen bacteria,generates organic compounds such as volatile fatty acids (acetic, propionic, butyric, VFA) and ammonia. The presence of VFA in the bioreactor medium at fairly low concentrations decreases the microbial population's metabolic reactions due to end-product inhibition. Technologies to remove VFA continuously from the bioreactor are of high interest. Several candidate technologies were analyzed, such as organic solvent liquid-liquid extraction, adsorption and/or ion exchange, dialysis, electrodialysis, and pressure driven membrane separation processes. The proposed technique for the on-line removal of VFA from the anaerobic bioreactor was a nanofiltration membrane recycle bioreactor. In order to establish the nanofiltration process performance variables before coupling it to the bioreactor, a series of experiments were carried out using a 10,000 MWCO tubular ceramic membrane module. The variables studied were the bioreactor slurry permeation characteristics, such as, the permeate flux, VFA and the nutrient removal rates as a function of applied transmembrane pressure, fluid recirculation velocity, suspended matter concentration, and process operating time. Results indicate that the permeate flux, VFA and nutrients removal rates are directly proportional to the fluid recirculation velocity in the range between 0.6 to 1.0 m/s, applied pressure when these are low than 1.5 bar, and inversely proportional to the total suspended solids concentration in the range between 23,466 to 34,880. At applied pressure higher than 1.5 bar the flux is not more linearly dependent due to concentration polarization and fouling effects over the membrange surface. It was also found

  4. Impact of stirred suspension bioreactor culture on the differentiation of murine embryonic stem cells into cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Shafa Mehdi

    2011-12-01

    Full Text Available Abstract Background Embryonic stem cells (ESCs can proliferate endlessly and are able to differentiate into all cell lineages that make up the adult organism. Under particular in vitro culture conditions, ESCs can be expanded and induced to differentiate into cardiomyocytes in stirred suspension bioreactors (SSBs. However, in using these systems we must be cognizant of the mechanical forces acting upon the cells. The effect of mechanical forces and shear stress on ESC pluripotency and differentiation has yet to be clarified. The purpose of this study was to investigate the impact of the suspension culture environment on ESC pluripotency during cardiomyocyte differentiation. Results Murine D3-MHC-neor ESCs formed embyroid bodies (EBs and differentiated into cardiomyocytes over 25 days in static culture and suspension bioreactors. G418 (Geneticin was used in both systems from day 10 to enrich for cardiomyocytes by eliminating non-resistant, undifferentiated cells. Treatment of EBs with 1 mM ascorbic acid and 0.5% dimethyl sulfoxide from day 3 markedly increased the number of beating EBs, which displayed spontaneous and cadenced contractile beating on day 11 in the bioreactor. Our results showed that the bioreactor differentiated cells displayed the characteristics of fully functional cardiomyocytes. Remarkably, however, our results demonstrated that the bioreactor differentiated ESCs retained their ability to express pluripotency markers, to form ESC-like colonies, and to generate teratomas upon transplantation, whereas the cells differentiated in adherent culture lost these characteristics. Conclusions This study demonstrates that although cardiomyocyte differentiation can be achieved in stirred suspension bioreactors, the addition of medium enhancers is not adequate to force complete differentiation as fluid shear forces appear to maintain a subpopulation of cells in a transient pluripotent state. The development of successful ESC

  5. A New Fluidized Bed Bioreactor Based on Diversion-Type Microcapsule Suspension for Bioartificial Liver Systems.

    Directory of Open Access Journals (Sweden)

    Juan Lu

    Full Text Available A fluidized bed bioreactor containing encapsulated hepatocytes may be a valuable alternative to a hollow fiber bioreactor for achieving the improved mass transfer and scale-up potential necessary for clinical use. However, a conventional fluidized bed bioreactor (FBB operating under high perfusion velocity is incapable of providing the desired performance due to the resulting damage to cell-containing microcapsules and large void volume. In this study, we developed a novel diversion-type microcapsule-suspension fluidized bed bioreactor (DMFBB. The void volume in the bioreactor and stability of alginate/chitosan microcapsules were investigated under different flow rates. Cell viability, synthesis and metabolism functions, and expression of metabolizing enzymes at transcriptional levels in an encapsulated hepatocyte line (C3A cells were determined. The void volume was significantly less in the novel bioreactor than in the conventional FBB. In addition, the microcapsules were less damaged in the DMFBB during the fluidization process as reflected by the results for microcapsule retention rates, swelling, and breakage. Encapsulated C3A cells exhibited greater viability and CYP1A2 and CYP3A4 activity in the DMFBB than in the FBB, although the increases in albumin and urea synthesis were less prominent. The transcription levels of several CYP450-related genes and an albumin-related gene were dramatically greater in cells in the DMFBB than in those in the FBB. Taken together, our results suggest that the DMFBB is a promising alternative for the design of a bioartificial liver system based on a fluidized bed bioreactor with encapsulated hepatocytes for treating patients with acute hepatic failure or other severe liver diseases.

  6. Vivre et survivre au bord des villes

    Directory of Open Access Journals (Sweden)

    Michel Péraldi

    1996-04-01

    Full Text Available De quels revenus vivent, ou plutôt survivent, les populations des quartiers dits défavorisés ? Telle est, malgré son apparente banalité, la question qui initie aujourd'hui une partie de nos recherches. Question banale en effet puisque les médias et le débat politique nous donnent une réponse sans appel, statistiquement fiable : dans ces univers sociaux où se croisent des communautés issues des plus récentes migrations et les fractions les plus fragiles économiquement des classes populaires fr...

  7. Un patrimoine ambivalent. La construction des traditions dans le Dictionnaire des coutumes, des traditions et des expressions égyptiennes de Ahmad Amîn

    OpenAIRE

    Perrin, Emmanuelle

    2010-01-01

    La réédition en 1999, dans une perspective patrimoniale, du Dictionnaire des coutumes, des traditions et des expressions égyptiennes (1953) par les instances officielles de la culture en Égypte offre matière à confronter cet ouvrage à la notion de patrimoine. D’une époque à l’autre, le changement de terminologie, avec le glissement des traditions au patrimoine, du national au populaire, est révélateur de la ductilité du sujet même de ce dictionnaire, lequel renvoie à la définition d’une « cul...

  8. Das Glück des Lehrers

    OpenAIRE

    Higgins, Christopher

    2002-01-01

    Im Rückgriff auf Bernard Williams' Unterscheidung zwischen Ethik und Moral [vertritt der Autor] die These, dass die Ethik des Lehrens sich mit der Beziehung zwischen dem Leben, dass [man] als Lehrer(in) führt, und dem guten Leben beschäftigt. Die Ethik des Lehrens führt die Frage: "Warum lehre ich?" mit der Frage: "Wie möchte ich leben?" zusammen. Die moderne Gegenüberstellung von egoistischem Interesse und Altruismus führt zu einer Vernachlässigung des Wohlergehens des Lehrers / der Lehrerin...

  9. Kooperative und hierarchische Erscheinungsformen des institutionellen Wandels

    OpenAIRE

    Consmüller, Nicola

    2013-01-01

    Die vorliegende Arbeit untersucht kooperative und hierarchische Erscheinungsformen des institutionellen Wandels am Beispiel des Anbaus von gentechnisch verändertem Bt-Mais MON810 in Deutschland. In den Jahren 2005 bis 2008 war der kommerzielle Anbau dieser Pflanze in Deutschland möglich, und überwiegend Landwirte in den ostdeutschen Bundesländern machten von dieser Möglichkeit der Bekämpfung des Maisschädlings Ostrinia nubilalis Hübn. (Maiszünsler) Gebrauch. Unter Zuhilfenahme des Analyserahm...

  10. Compétitivité des territoires ruraux

    OpenAIRE

    Filippi, Marie Denise

    2011-01-01

    Les enjeux de la compétitivité des entreprises et des territoires ruraux sont liés aux bouleversements actuels : la nouvelle PAC, la mondialisation, la volatilité des prix… autant d’éléments représentant des menaces mais aussi des opportunités. Ce projet a pour objectif d’analyser les sources de la compétitivité des territoires ruraux. En termes scientifiques, il vise à étudier les dynamiques organisationnelles des entreprises agricoles pour comprendre les déterminants des processus de compét...

  11. Use of a Three-Dimensional Reactive Solute Transport Model for Evaluation of Bioreactor Placement in Stream Restoration.

    Science.gov (United States)

    Cui, Zhengtao; Welty, Claire; Gold, Arthur J; Groffman, Peter M; Kaushal, Sujay S; Miller, Andrew J

    2016-05-01

    A three-dimensional groundwater flow and multispecies reactive transport model was used to strategically design placement of bioreactors in the subsurface to achieve maximum removal of nitrate along restored stream reaches. Two hypothetical stream restoration scenarios were evaluated over stream reaches of 40 and 94 m: a step-pool scenario and a channel re-meandering scenario. For the step-pool scenario, bioreactors were placed at locations where mass fluxes of groundwater and nitrate were highest. Bioreactors installed over 50% of the total channel length of a step-pool scenario (located to intercept maximum groundwater and nitrate mass flux) removed nitrate-N entering the channel at a rate of 36.5 kg N yr (100 g N d), achieving about 65% of the removal of a whole-length bioreactor. Bioreactor placement for the re-meandering scenario was designed using a criterion of either highest nitrate mass flux or highest groundwater flux, but not both, because they did not occur together. Bioreactors installed at maximum nitrate flux locations (53% of the total channel length) on the western bank removed nitrate-N entering the channel at 62.0 kg N yr (170 g N d), achieving 85% of nitrate-N removal of whole-length bioreactors for the re-meandering scenario. Bioreactors installed at maximum groundwater flux locations on the western bank along approximately 40% of the re-meandering channel achieved about 65% of nitrate removal of whole-length bioreactors. Placing bioreactors at maximum nitrate flux locations improved denitrification efficiency. Due to low groundwater velocities, bioreactor nitrate-N removal was found to be nitrate limited for all scenarios.

  12. Transport quantique dans des nanostructures

    Science.gov (United States)

    Naud, C.

    2002-09-01

    structure des oscillations de conductance en fonction du flux du champ magnétique de période h/e dont l'amplitude est beaucoup plus importante que celle mesurée sur un réseau carré de même dimension. Cette différence constitue une signature d'un effet de localisation induit par le champ magnétique sur la topologie mathcal{T}3. Pour des valeurs spécifiques du champ magnétique, du fait des interférences destructives Aharonov-Bohm, la propagation des fonctions d'ondes est limitée à un ensemble fini de cellule du réseau appelé cage. De la dépendance en température des oscillations de période h/e mesurées sur le réseau mathcal{T}3 nous avons tiré une longueur caractéristique qui peut être rattachée au périmètre des cages. Un phénomène inattendu fut l'observation, pour des champs magnétiques plus importants, d'un doublement de fréquence des oscillations. Ces oscillations de période h/2e pouvant avoir une amplitude supérieure aux oscillations de période h/e, une interprétation en terme d'harmonique n'est pas possible. Enfin, l'influence de la largeur électrique des fils constituant le réseau et donc celle du nombre de canaux par brin a été étudiée en réalisant des grilles électrostatique. Les variations de l'amplitude des signaux en h/e et h/2e en fonction de la tension de grille ont été mesurés.

  13. Le mouvement des modèles en histoire et philosophie des neurosciences

    OpenAIRE

    Andrieu, Bernard

    2005-01-01

    L’histoire des neurosciences devient peu à peu une discipline à part entière, en France du moins, car dans le monde anglo-saxon la philosophie de l’esprit et l’expansion des sciences de la cognition ont toujours été accompagnés d’une formation et d’une production en histoire des neurosciences, au point que des collections de revues et de livres y sont consacrés. Mais derrière cette tradition critique et épistémologique, se cachent différents types d’écriture de l’histoire des neurosciences. ...

  14. Fusions et acquisitions et richesse des actionnaires : le cas des banques européennes

    OpenAIRE

    Diaw, Abdourahmane

    2012-01-01

    Cette thèse porte sur le lien entre fusions et acquisitions et création de valeur actionnariale. La problématique consiste à analyser ce paradoxe qui est le recours des banques aux fusions et acquisitions en dépit des résultats des recherches scientifiques qui en démontrent le peu d’efficacité en termes de rentabilité actionnariale. De prime abord nous procédons à une analyse théorique des fusions et acquisitions bancaires en insistant sur des aspects particuliers comme l’évolution du phénomè...

  15. Using XML to encode TMA DES metadata

    Directory of Open Access Journals (Sweden)

    Oliver Lyttleton

    2011-01-01

    Full Text Available Background: The Tissue Microarray Data Exchange Specification (TMA DES is an XML specification for encoding TMA experiment data. While TMA DES data is encoded in XML, the files that describe its syntax, structure, and semantics are not. The DTD format is used to describe the syntax and structure of TMA DES, and the ISO 11179 format is used to define the semantics of TMA DES. However, XML Schema can be used in place of DTDs, and another XML encoded format, RDF, can be used in place of ISO 11179. Encoding all TMA DES data and metadata in XML would simplify the development and usage of programs which validate and parse TMA DES data. XML Schema has advantages over DTDs such as support for data types, and a more powerful means of specifying constraints on data values. An advantage of RDF encoded in XML over ISO 11179 is that XML defines rules for encoding data, whereas ISO 11179 does not. Materials and Methods: We created an XML Schema version of the TMA DES DTD. We wrote a program that converted ISO 11179 definitions to RDF encoded in XML, and used it to convert the TMA DES ISO 11179 definitions to RDF. Results: We validated a sample TMA DES XML file that was supplied with the publication that originally specified TMA DES using our XML Schema. We successfully validated the RDF produced by our ISO 11179 converter with the W3C RDF validation service. Conclusions: All TMA DES data could be encoded using XML, which simplifies its processing. XML Schema allows datatypes and valid value ranges to be specified for CDEs, which enables a wider range of error checking to be performed using XML Schemas than could be performed using DTDs.

  16. Biological reduction of nitrates in wastewaters from nuclear processing using a fluidized-bed bioreactor

    International Nuclear Information System (INIS)

    There are a number of nitrate-containing wastewater sources, as concentrated as 30 wt.% NO3- and as large as 2000 m3/day, in the nuclear fuel cycle. The biological reduction of nitrate in wastewater to gaseous nitrogen, accompanied by the oxidation of a nutrient carbon source to gaseous carbon dioxide, is an ecologically sound and cost-effective method of treating wastewaters containing nitrates. These nitrate-containing wastewater sources can be successfully biologically denitrified to meet discharge standards in the range of 10 to 20 gN(NO3-)/m3 by the use of a fluidized-bed bioreactor. The denitrification bacteria are a mixed culture derived from garden soil; the major strain is Pseudomonas. In the fluidized-bed bioreactor the bacteria are allowed to attach to 0.25- to 0.50-mm-diam coal fluidization particles, which are then fluidized by the upward flow of influent wastewater. Maintaining the bacteria-to-coal weight ratio at approximately 1:10 results in a bioreactor bacteria loading of greater than 20,000 g/m3. This paper describes the results of a biodenitrification R and D program based on the use of fluidized bioreactors capable of operating at nitrate levels up to 7000 g/m3 and achieving denitrification rates as high as 80 g N(NO3-) per day per liter of empty bioreactor volume. 4 figures, 7 tables

  17. Mathematical modeling and experimental testing of three bioreactor configurations based on windkessel models

    Directory of Open Access Journals (Sweden)

    Genevieve Lachance

    2010-02-01

    Full Text Available This paper presents an experimental study of three bioreactor configurations. The bioreactor is intended to be used for the development of tissue-engineered heart valve substitutes. Therefore it must be able to reproduce physiological flow and pressure waveforms accurately. A detailed analysis of three bioreactor arrangements is presented using mathematical models based on the windkessel (WK approach. First, a review of the many applications of this approach in medical studies enhances its fundamental nature and its usefulness. Then the models are developed with reference to the actual components of the bioreactor. This study emphasizes different conflicting issues arising in the design process of a bioreactor for biomedical purposes, where an optimization process is essential to reach a compromise satisfying all conditions. Two important aspects are the need for a simple system providing ease of use and long-term sterility, opposed to the need for an advanced (thus more complex architecture capable of a more accurate reproduction of the physiological environment. Three classic WK architectures are analyzed, and experimental results enhance the advantages and limitations of each one.

  18. Packed Bed Bioreactor for the Isolation and Expansion of Placental-Derived Mesenchymal Stromal Cells.

    Science.gov (United States)

    Osiecki, Michael J; Michl, Thomas D; Kul Babur, Betul; Kabiri, Mahboubeh; Atkinson, Kerry; Lott, William B; Griesser, Hans J; Doran, Michael R

    2015-01-01

    Large numbers of Mesenchymal stem/stromal cells (MSCs) are required for clinical relevant doses to treat a number of diseases. To economically manufacture these MSCs, an automated bioreactor system will be required. Herein we describe the development of a scalable closed-system, packed bed bioreactor suitable for large-scale MSCs expansion. The packed bed was formed from fused polystyrene pellets that were air plasma treated to endow them with a surface chemistry similar to traditional tissue culture plastic. The packed bed was encased within a gas permeable shell to decouple the medium nutrient supply and gas exchange. This enabled a significant reduction in medium flow rates, thus reducing shear and even facilitating single pass medium exchange. The system was optimised in a small-scale bioreactor format (160 cm2) with murine-derived green fluorescent protein-expressing MSCs, and then scaled-up to a 2800 cm2 format. We demonstrated that placental derived MSCs could be isolated directly within the bioreactor and subsequently expanded. Our results demonstrate that the closed system large-scale packed bed bioreactor is an effective and scalable tool for large-scale isolation and expansion of MSCs. PMID:26660475

  19. Production of Calcaride A by Calcarisporium sp. in Shaken Flasks and Stirred Bioreactors

    Directory of Open Access Journals (Sweden)

    Anu Tamminen

    2015-06-01

    Full Text Available Increased interest in marine resources has led to increased screening of marine fungi for novel bioactive compounds and considerable effort is being invested in discovering these metabolites. For compound discovery, small-scale cultures are adequate, but agitated bioreactors are desirable for larger-scale production. Calcarisporium sp. KF525 has recently been described to produce calcaride A, a cyclic polyester with antibiotic activity, in agitated flasks. Here, we describe improvements in the production of calcaride A in both flasks (13-fold improvement and stirred bioreactors (200-fold improvement. Production of calcaride A in bioreactors was initially substantially lower than in shaken flasks. The cultivation pH (reduced from 6.8 to <5.4, carbon source (sucrose replacing glucose, C/N ratio and nature of mycelial growth (pellets or filaments were important in improving calcaride A production. Up to 4.5 mg·g−1 biomass (85 mg·L−1 calcaride A were produced in the bioreactor, which was only slightly less than in shaken flasks (14 mg·g−1, 100 mg·L−1. The results demonstrate that a scalable process for calcaride A production could be developed using an iterative approach with flasks and bioreactors.

  20. In vivo bone regeneration using tubular perfusion system bioreactor cultured nanofibrous scaffolds.

    Science.gov (United States)

    Yeatts, Andrew B; Both, Sanne K; Yang, Wanxun; Alghamdi, Hamdan S; Yang, Fang; Fisher, John P; Jansen, John A

    2014-01-01

    The use of bioreactors for the in vitro culture of constructs for bone tissue engineering has become prevalent as these systems may improve the growth and differentiation of a cultured cell population. Here we utilize a tubular perfusion system (TPS) bioreactor for the in vitro culture of human mesenchymal stem cells (hMSCs) and implant the cultured constructs into rat femoral condyle defects. Using nanofibrous electrospun poly(lactic-co-glycolic acid)/poly(ε-caprolactone) scaffolds, hMSCs were cultured for 10 days in vitro in the TPS bioreactor with cellular and acellular scaffolds cultured statically for 10 days as a control. After 3 and 6 weeks of in vivo culture, explants were removed and subjected to histomorphometric analysis. Results indicated more rapid bone regeneration in defects implanted with bioreactor cultured scaffolds with a new bone area of 1.23 ± 0.35 mm(2) at 21 days compared to 0.99 ± 0.43 mm(2) and 0.50 ± 0.29 mm(2) in defects implanted with statically cultured scaffolds and acellular scaffolds, respectively. At the 21 day timepoint, statistical differences (pbioreactor to improve bone tissue regeneration and highlights the benefits of utilizing perfusion bioreactor systems to culture MSCs for bone tissue engineering.

  1. X-ray phase contrast imaging of calcified tissue and biomaterial structure in bioreactor engineered tissues.

    Science.gov (United States)

    Appel, Alyssa A; Larson, Jeffery C; Garson, Alfred B; Guan, Huifeng; Zhong, Zhong; Nguyen, Bao-Ngoc B; Fisher, John P; Anastasio, Mark A; Brey, Eric M

    2015-03-01

    Tissues engineered in bioreactor systems have been used clinically to replace damaged tissues and organs. In addition, these systems are under continued development for many tissue engineering applications. The ability to quantitatively assess material structure and tissue formation is critical for evaluating bioreactor efficacy and for preimplantation assessment of tissue quality. Techniques that allow for the nondestructive and longitudinal monitoring of large engineered tissues within the bioreactor systems will be essential for the translation of these strategies to viable clinical therapies. X-ray Phase Contrast (XPC) imaging techniques have shown tremendous promise for a number of biomedical applications owing to their ability to provide image contrast based on multiple X-ray properties, including absorption, refraction, and scatter. In this research, mesenchymal stem cell-seeded alginate hydrogels were prepared and cultured under osteogenic conditions in a perfusion bioreactor. The constructs were imaged at various time points using XPC microcomputed tomography (µCT). Imaging was performed with systems using both synchrotron- and tube-based X-ray sources. XPC µCT allowed for simultaneous three-dimensional (3D) quantification of hydrogel size and mineralization, as well as spatial information on hydrogel structure and mineralization. Samples were processed for histological evaluation and XPC showed similar features to histology and quantitative analysis consistent with the histomorphometry. These results provide evidence of the significant potential of techniques based on XPC for noninvasive 3D imaging engineered tissues grown in bioreactors.

  2. Novel disposable flexible bioreactor for Escherichia coli culture in orbital shaking incubator.

    Science.gov (United States)

    Yang, Ting; Huang, Yue; Han, Zhiqiang; Liu, Huitao; Zhang, Rui; Xu, Yuming

    2013-10-01

    Erlenmeyer flask or conical flask, usually made of glass, is widely used for laboratory scale suspension culture of microorganism, such as Escherichia Coli and yeast. Due to being non-disposable culture vessel, it has to be cleaned, packaged and sterilized prior to use, which are time, labor and energy consuming work, and has the potential risk of cross-contamination. Despite the rigid plastic conical flasks are possible for single use, they are not economically effective and produce more waste. To overcome these drawbacks, here we successfully developed a novel disposable flexible bioreactor with a plastic film through a thermo-fusion technique. With a triangular pyramid shape, the bioreactor enabled itself to keep a three-dimensional internal space without needing air inflation and well adapted to the commercial available orbital shaker. Unlike the conventional rigid conical flasks and other reported flexible flasks, which had to be fixed in the shaker, the flexible bioreactor could keep sitting on the silicone pad-carpeted platform of the orbital shaker steadily without any fixation needed at the shaking speeds below 250 rpm, thus making it simple to handle. Compared with the traditional conical glass flasks, the innovative flexible bioreactors achieved a significant higher efficiency in bacteria growth and oxygen transfer rates. In conclusion, the novel flexible bioreactor is an ideal disposable culture vessel for microorganism suspension culture at laboratory scale and holds a promising potential to replace the glass flask and rigid plastic flask in the future.

  3. [Technological characteristics of bioreactor landfill with aeration in the upper layer].

    Science.gov (United States)

    Tian, Ying; Wang, Shen; Xu, Qi-Yong

    2014-11-01

    In order to study the effects of upper-layer aerobic pretreatment in bioreactors on refuse degradation, leachate condition and methane production, two simulated columns were constructed, including traditional anaerobic bioreactor A1 and hybrid bioreactor C1 with aeration pretreatment in the upper layer. Results indicated that A1 was seriously inhibited by the accumulation of volatile fatty acids (VFA) with nearly no methane production and slower settlements. At the end of operations, refuse in A1 only deposited 5.4 cm which was less than half of that in C1. And up to 70 000 mg x L(-1) COD and 30 000 mg x L(-1) VFA could be monitored in the leachate. On the contrary, aerobic pretreatment effectively improved the removal of high VFA concentrations and remarkably accelerated the degradation rate. In bioreactor C1, COD and VFA concentrations were reduced to less than 14000 mg x L(-1) and 8900 mg x L(-1) at the end of the experiment, respectively. And about 61 976 mL methane gases were produced since aeration ceased on day 60 with its methane recovery efficiency rising to over 95%. However, the performance of hybrid bioreactors was still closely related to its operation conditions, such as aeration supply and leachate recirculation. Therefore, in order to guarantee better performance, appropriate aeration and leachate operations need to be provided.

  4. Packed Bed Bioreactor for the Isolation and Expansion of Placental-Derived Mesenchymal Stromal Cells.

    Science.gov (United States)

    Osiecki, Michael J; Michl, Thomas D; Kul Babur, Betul; Kabiri, Mahboubeh; Atkinson, Kerry; Lott, William B; Griesser, Hans J; Doran, Michael R

    2015-01-01

    Large numbers of Mesenchymal stem/stromal cells (MSCs) are required for clinical relevant doses to treat a number of diseases. To economically manufacture these MSCs, an automated bioreactor system will be required. Herein we describe the development of a scalable closed-system, packed bed bioreactor suitable for large-scale MSCs expansion. The packed bed was formed from fused polystyrene pellets that were air plasma treated to endow them with a surface chemistry similar to traditional tissue culture plastic. The packed bed was encased within a gas permeable shell to decouple the medium nutrient supply and gas exchange. This enabled a significant reduction in medium flow rates, thus reducing shear and even facilitating single pass medium exchange. The system was optimised in a small-scale bioreactor format (160 cm2) with murine-derived green fluorescent protein-expressing MSCs, and then scaled-up to a 2800 cm2 format. We demonstrated that placental derived MSCs could be isolated directly within the bioreactor and subsequently expanded. Our results demonstrate that the closed system large-scale packed bed bioreactor is an effective and scalable tool for large-scale isolation and expansion of MSCs.

  5. X-ray Phase Contrast Imaging of Calcified Tissue and Biomaterial Structure in Bioreactor Engineered Tissues

    Energy Technology Data Exchange (ETDEWEB)

    Appel, Alyssa A. [Illinois Inst. of Technology, Chicago, IL (United States); Edward Hines Jr. VA Hospital, IL (United States); Larson, Jeffery C. [Illinois Inst. of Technology, Chicago, IL (United States); Edward Hines Jr. VA Hospital, IL (United States); Garson, III, Alfred B. [George Washington Univ., Washington, DC (United States); Guan, Huifeng [George Washington Univ., Washington, DC (United States); Zhong, Zhong [Brookhaven National Lab. (BNL), Upton, NY (United States); Nguyen, Bao-Ngoc [Univ. of Maryland, College Park, MD (United States); Fisher, John P. [Univ. of Maryland, College Park, MD (United States); Anastasio, Mark A. [George Washington Univ., Washington, DC (United States); Brey, Eric M. [Illinois Inst. of Technology, Chicago, IL (United States); Edward Hines Jr. VA Hospital, IL (United States)

    2014-11-04

    Tissues engineered in bioreactor systems have been used clinically to replace damaged tissues and organs. In addition, these systems are under continued development for many tissue engineering applications. The ability to quantitatively assess material structure and tissue formation is critical for evaluating bioreactor efficacy and for preimplantation assessment of tissue quality. These techniques allow for the nondestructive and longitudinal monitoring of large engineered tissues within the bioreactor systems and will be essential for the translation of these strategies to viable clinical therapies. X-ray Phase Contrast (XPC) imaging techniques have shown tremendous promise for a number of biomedical applications owing to their ability to provide image contrast based on multiple X-ray properties, including absorption, refraction, and scatter. In this research, mesenchymal stem cell-seeded alginate hydrogels were prepared and cultured under osteogenic conditions in a perfusion bioreactor. The constructs were imaged at various time points using XPC microcomputed tomography (µCT). Imaging was performed with systems using both synchrotron- and tube-based X-ray sources. XPC µCT allowed for simultaneous three-dimensional (3D) quantification of hydrogel size and mineralization, as well as spatial information on hydrogel structure and mineralization. Samples were processed for histological evaluation and XPC showed similar features to histology and quantitative analysis consistent with the histomorphometry. Furthermore, these results provide evidence of the significant potential of techniques based on XPC for noninvasive 3D imaging engineered tissues grown in bioreactors.

  6. Development of a Cyclic Strain Bioreactor for Mechanical Enhancement and Assessment of Bioengineered Myocardial Constructs.

    Science.gov (United States)

    Salazar, Betsy H; Cashion, Avery T; Dennis, Robert G; Birla, Ravi K

    2015-12-01

    The purpose of this study was to develop enabling bioreactor technologies using a novel voice coil actuator system for investigating the effects of periodic strain on cardiac patches fabricated with rat cardiomyocytes. The bioengineered muscle constructs used in this study were formed by culturing rat neonatal primary cardiac cells on a fibrin gel. The physical design of the bioreactor was initially conceived using Solidworks to test clearances and perform structural strain analysis. Once the software design phase was completed the bioreactor was assembled using a combination of commercially available, custom machined, and 3-D printed parts. We utilized the bioreactor to evaluate the effect of a 4-h stretch protocol on the contractile properties of the tissue after which immunohistological assessment of the tissue was also performed. An increase in contractile force was observed after the strain protocol of 10% stretch at 1 Hz, with no significant increase observed in the control group. Additionally, an increase in cardiac myofibril alignment, connexin 43 expression, and collagen type I distribution were noted. In this study we demonstrated the effectiveness of a new bioreactor design to improve contractility of engineered cardiac muscle tissue.

  7. Production of Calcaride A by Calcarisporium sp. in Shaken Flasks and Stirred Bioreactors

    Science.gov (United States)

    Tamminen, Anu; Wang, Yanming; Wiebe, Marilyn G.

    2015-01-01

    Increased interest in marine resources has led to increased screening of marine fungi for novel bioactive compounds and considerable effort is being invested in discovering these metabolites. For compound discovery, small-scale cultures are adequate, but agitated bioreactors are desirable for larger-scale production. Calcarisporium sp. KF525 has recently been described to produce calcaride A, a cyclic polyester with antibiotic activity, in agitated flasks. Here, we describe improvements in the production of calcaride A in both flasks (13-fold improvement) and stirred bioreactors (200-fold improvement). Production of calcaride A in bioreactors was initially substantially lower than in shaken flasks. The cultivation pH (reduced from 6.8 to <5.4), carbon source (sucrose replacing glucose), C/N ratio and nature of mycelial growth (pellets or filaments) were important in improving calcaride A production. Up to 4.5 mg·g−1 biomass (85 mg·L−1) calcaride A were produced in the bioreactor, which was only slightly less than in shaken flasks (14 mg·g−1, 100 mg·L−1). The results demonstrate that a scalable process for calcaride A production could be developed using an iterative approach with flasks and bioreactors. PMID:26114617

  8. Design considerations and challenges for mechanical stretch bioreactors in tissue engineering.

    Science.gov (United States)

    Lei, Ying; Ferdous, Zannatul

    2016-05-01

    With the increase in average life expectancy and growing aging population, lack of functional grafts for replacement surgeries has become a severe problem. Engineered tissues are a promising alternative to this problem because they can mimic the physiological function of the native tissues and be cultured on demand. Cyclic stretch is important for developing many engineered tissues such as hearts, heart valves, muscles, and bones. Thus a variety of stretch bioreactors and corresponding scaffolds have been designed and tested to study the underlying mechanism of tissue formation and to optimize the mechanical conditions applied to the engineered tissues. In this review, we look at various designs of stretch bioreactors and common scaffolds and offer insights for future improvements in tissue engineering applications. First, we summarize the requirements and common configuration of stretch bioreactors. Next, we present the features of different actuating and motion transforming systems and their applications. Since most bioreactors must measure detailed distributions of loads and deformations on engineered tissues, techniques with high accuracy, precision, and frequency have been developed. We also cover the key points in designing culture chambers, nutrition exchanging systems, and regimens used for specific tissues. Since scaffolds are essential for providing biophysical microenvironments for residing cells, we discuss materials and technologies used in fabricating scaffolds to mimic anisotropic native tissues, including decellularized tissues, hydrogels, biocompatible polymers, electrospinning, and 3D bioprinting techniques. Finally, we present the potential future directions for improving stretch bioreactors and scaffolds. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:543-553, 2016.

  9. A Versatile Bioreactor for Dynamic Suspension Cell Culture. Application to the Culture of Cancer Cell Spheroids.

    Science.gov (United States)

    Massai, Diana; Isu, Giuseppe; Madeddu, Denise; Cerino, Giulia; Falco, Angela; Frati, Caterina; Gallo, Diego; Deriu, Marco A; Falvo D'Urso Labate, Giuseppe; Quaini, Federico; Audenino, Alberto; Morbiducci, Umberto

    2016-01-01

    A versatile bioreactor suitable for dynamic suspension cell culture under tunable shear stress conditions has been developed and preliminarily tested culturing cancer cell spheroids. By adopting simple technological solutions and avoiding rotating components, the bioreactor exploits the laminar hydrodynamics establishing within the culture chamber enabling dynamic cell suspension in an environment favourable to mass transport, under a wide range of tunable shear stress conditions. The design phase of the device has been supported by multiphysics modelling and has provided a comprehensive analysis of the operating principles of the bioreactor. Moreover, an explanatory example is herein presented with multiphysics simulations used to set the proper bioreactor operating conditions for preliminary in vitro biological tests on a human lung carcinoma cell line. The biological results demonstrate that the ultralow shear dynamic suspension provided by the device is beneficial for culturing cancer cell spheroids. In comparison to the static suspension control, dynamic cell suspension preserves morphological features, promotes intercellular connection, increases spheroid size (2.4-fold increase) and number of cycling cells (1.58-fold increase), and reduces double strand DNA damage (1.5-fold reduction). It is envisioned that the versatility of this bioreactor could allow investigation and expansion of different cell types in the future. PMID:27144306

  10. Removal of trace organics by anaerobic membrane bioreactors.

    Science.gov (United States)

    Monsalvo, Victor M; McDonald, James A; Khan, Stuart J; Le-Clech, Pierre

    2014-02-01

    The biological removal of 38 trace organics (pharmaceuticals, endocrine disruptors, personal care products and pesticides) was studied in an anaerobic membrane bioreactor (AnMBR). This work presents complete information on the different removal mechanisms involved in the removal of trace organics in this process. In particular, it is focused on advanced characterization of the relative amount of TO accumulated within the fouling layers formed on the membranes. The results show that only 9 out of 38 compounds were removed by more than 90% while 23 compounds were removed by less than 50%. These compounds are therefore removed in an AnMBR biologically and partially adsorbed and retained by flocs and the deposition developed on the membranes, respectively. A total amount of 288 mg of trace organics was retained per m(2) of membrane, which were distributed along the different fouling layers. Among the trace organics analyzed, 17α-ethynylestradiol, estrone, octylphenol and bisphenol A were the most retained by the fouling layers. Among the fouling layers deposited on the membranes, the non-readily detachable layer has been identified as the main barrier for trace organics.

  11. Evolution of a phase separated gravity independent bioreactor

    Science.gov (United States)

    Villeneuve, Peter E.; Dunlop, Eric H.

    The evolution of a phase-separated gravity-independent bioreactor is described. The initial prototype, a zero head-space manifold silicone membrane based reactor, maintained large diffusional resistances. Obtaining oxygen transfer rates needed to support carbon-recycling aerobic microbes is impossible if large resistances are maintained. Next generation designs (Mark I and II) mimic heat exchanger design to promote turbulence at the tubing-liquid interface, thereby reducing liquid and gas side diffusional resistances. While oxygen transfer rates increased by a factor of ten, liquid channeling prevented further increases. To overcome these problems, a Mark III reactor was developed which maintains inverted phases, i.e., media flows inside the silicone tubing, oxygen gas is applied external to the tubing. This enhances design through changes in gas side driving force concentration and liquid side turbulence levels. Combining an applied external pressure of four atmospheres with increased Reynolds numbers resulted in oxygen transfer intensities of 232 mmol O2/l/h (1000 times greater than first prototype and comparable to a conventional fermenter). A 1.0 liter Mark III reactor can potentially deliver oxygen supplies necessary to support cell cultures needed to recycle a 10 astronaut carbon load continuously.

  12. Comparison of textile dye treatment by biosorption and membrane bioreactor.

    Science.gov (United States)

    Chamam, B; Heran, M; Amar, R Ben; Grasmick, A

    2007-12-01

    The Cassulfon CMR is a sulphuric textile dye mainly used to colour "jeans". It has a dark black-blue colour, with high intensity of colour and high mineral compounds (71% of dry matter). Direct filtration experiments were carried out to quantity the capacity of macro porous membranes (1.2, 0.2 or 0.1 microm) to separate organic matter and colour from the effluent. The results show that no direct membrane filtration was efficient. To evaluate the capacity of a biological way for the elimination of this dye, batch experiments were performed to quantify the dye sorption capacity on activated sludge. Results show the high capacity of the biomass to adsorb colour (more than 4gCOD gMLVSS(-1)) while 15% of COD remain in the soluble fraction. To evaluate the biodegradability potential of the sludge, continuous operations were carried out in a membrane bioreactor (MBR). Results confirm the very high MBR potential to treat such dye effluents. During operations, the organic load was progressively increased from 0.33 to 1.33 kg m(-3) d(-1) and the permeate quality was always free of suspended solids or turbidity. Moreover, the permeate COD values were always lower than 60 mg l(-1) and small permeate coloration only appeared during malfunctioning periods.

  13. Use of NASA Bioreactor in Engineering Tissue for Bone Repair

    Science.gov (United States)

    Duke, Pauline

    1998-01-01

    This study was proposed in search for a new alternative for bone replacement or repair. Because the systems commonly used in repair of bony defects form bone by going through a cartilaginous phase, implantation of a piece of cartilage could enhance the healing process by having a more advanced starting point. However, cartilage has seldom been used to replace bone due, in part, to the limitations in conventional culture systems that did not allow production of enough tissue for implants. The NASA-developed bioreactors known as STLV (Slow Turning Lateral Vessel) provide homogeneous distribution of cells, nutrients, and waste products, with less damaging turbulence and shear forces than conventional systems. Cultures under these conditions have higher growth rates, viability, and longevity, allowing larger "tissue-like" aggregates to form, thus opening the possibilities of producing enough tissue for implantation, along with the inherent advantages of in vitro manipulations. To assure large numbers of cells and to eliminate the use of timed embryos, we proposed to use an immortalized mouse limb bud cell line as the source of cells.

  14. Mechanism of calcium mitigating membrane fouling in submerged membrane bioreactors

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hanmin; XIA Jie; YANG Yang; WANG Zixing; YANG Fenglin

    2009-01-01

    Two parallel membrane bioreactors (MBRs) were operated under different calcium dosages (168.5, 27 mg/L) to gain a better understanding of the mechanism of retarding membrane fouling by the addition of calcium.The results showed that the particle size of sludge flocs increased and the particle size distribution tended to be narrow at the optimum dosage (168.5 mg/L).Calcium was effective in decreasing loosely bound extracellular polymeric substances (LB-EPS) in microbial flocs and soluble microbial products (SMP) in the supernatant at the dosage of 168.5 mg/L by strengthening the neutralization and bridging of EPS with flocs.Furthermore, the amount of CODS and CODC decreased in both the mixed liquor and the fouling cake layer on the membrane surface.In order to compare the filtration characteristics of cake layers from the MBRs with the two calcium dosages, the specific cake resistance and the compressibility coefficient were measured.The specific cake resistance from the MBR with optimum dosage (168.5 mg/L) was distinctly lower than that with low dosage (27 mg/L).The compressibility coefficient of the cake layers under different dosages were respectively attained as 0.65, 0.91.Scanning electron microscopy (SEM) and three-dimensional confocal scanning laser microscope analysis (CLSM) images were utilized to observe the gel layer directly.

  15. Sulfide oxidation in fluidized bed bioreactor using nylon support material

    Institute of Scientific and Technical Information of China (English)

    Varsha Midha; M K Jha; Apurba Dey

    2012-01-01

    A continuous fluidized bed bioreactor(FBBR)with nylon support particles was used to treat synthetic sulfide wastewater at different hydraulic retention time of 25,50 and 75 min and upflow velocity of 14,17 and 20 m/hr.The effects of upflow velocity,hydraulic retention time and reactor operation time on sulfide oxidation rate were studied using statistical model.Mixed culture obtained from the activated sludge,taken from tannery effluent treatment plant,was used as a source for microorganisms.The diameter and density of the nylon particles were 2-3 mm and 1140 kg/m3,respectively.Experiments were carried out in the reactor at a temperature of(30± 2)℃,at a fixed bed height of 16 cm after the formation of biofilm on the surface of support particles.Biofilm thickness reached(42±3)μm after 15 days from reactor start-up.The sulfide oxidation,sulfate and sulfur formation is examined at all hydraulic retention times and upflow velocities.The results indicated that almost 90%-92% sulfide oxidation was achieved at all hydraulic retention times.Statistical model could explain 94% of the variability and analysis of variance showed that upflow velocity and hydraulic retention time slightly affected the sulfide oxidation rate.The highest sulfide oxidation of 92% with 70% sulfur was obtained at hydraulic retention time of 75 min and upflow velocity of 14 m/hr.

  16. Analysis of fouling mechanisms in anaerobic membrane bioreactors.

    Science.gov (United States)

    Charfi, Amine; Ben Amar, Nihel; Harmand, Jérôme

    2012-05-15

    In this paper, we investigate the fouling mechanisms responsible for MF and UF membrane flux decline in Anaerobic Membrane Bioreactors (AnMBR). We have used the fouling mechanism models proposed by Hermia (1982), namely pore constriction, cake formation, complete blocking and intermediate blocking. Based on an optimization approach and using experimental data extracted from the literature, we propose a systematic procedure for identifying the most likely fouling mechanism in play. Short-term as well as long-term experiments are considered and discussed. It was found that short-term experiments are usually characterized by two fouling phases during which the same fouling mechanism or two different mechanisms affect the process. In contrast, in long-term experiments involving cleaning cycles, membrane fouling appears to be better ascribed to one phase only. The impact of abiotic parameters on membrane fouling mechanisms is reviewed and discussed in the light of these results. Finally, it is shown that the mechanism most responsible for membrane fouling in an AnMBR is cake formation. This main result will be useful for the future development of simple integrated models for optimization and control. PMID:22397816

  17. Autotrophic ammonia removal from landfill leachate in anaerobic membrane bioreactor.

    Science.gov (United States)

    Suneethi, S; Joseph, Kurian

    2013-01-01

    Anaerobic ammonium oxidation (ANAMMOX) process, an advanced biological nitrogen removal, removes ammonia using nitrite as the electron acceptor without oxygen. In this paper, ANAMMOX process was adopted for removing NH4+-N from landfill leachate having low COD using anaerobic membrane bioreactor (AnMBR). The AnMBR was optimized for nitrogen loading rate (NLR) varying from 0.025 to 5 kg NH4+-N/m3/d with hydraulic retention time (HRT) ranging from 1 to 3d. NH4+-N removal efficacy of 85.13 +/- 9.67% with the mean nitrogen removal rate of 5.54 +/- 0.63 kg NH4+-N/m3/d was achieved with NLR of 6.51 +/- 0.20kg NH4+-N/m3/d at 1.5 d HRT. The nitrogen transformation intermediates in the form of hydrazine (N2H4) and hydroxylamine (NH2OH) were 0.008 +/- 0.005 and 0.006 +/- 0.001 mg/l, respectively, indicating co-existence of aerobic ammonia oxidizers and ANAMMOX. The free ammonia (NH3) and free nitrous acid (HNO2) concentrations were 26.61 +/- 16.54 mg/l and (1.66 +/- 0.95) x 10(-5) mg/l, preventing NO2(-)-N oxidation to NO3(-)-N enabling sustained NH4+-N removal. PMID:24617075

  18. Removal of trace organics by anaerobic membrane bioreactors.

    Science.gov (United States)

    Monsalvo, Victor M; McDonald, James A; Khan, Stuart J; Le-Clech, Pierre

    2014-02-01

    The biological removal of 38 trace organics (pharmaceuticals, endocrine disruptors, personal care products and pesticides) was studied in an anaerobic membrane bioreactor (AnMBR). This work presents complete information on the different removal mechanisms involved in the removal of trace organics in this process. In particular, it is focused on advanced characterization of the relative amount of TO accumulated within the fouling layers formed on the membranes. The results show that only 9 out of 38 compounds were removed by more than 90% while 23 compounds were removed by less than 50%. These compounds are therefore removed in an AnMBR biologically and partially adsorbed and retained by flocs and the deposition developed on the membranes, respectively. A total amount of 288 mg of trace organics was retained per m(2) of membrane, which were distributed along the different fouling layers. Among the trace organics analyzed, 17α-ethynylestradiol, estrone, octylphenol and bisphenol A were the most retained by the fouling layers. Among the fouling layers deposited on the membranes, the non-readily detachable layer has been identified as the main barrier for trace organics. PMID:24321247

  19. Transient maintenance in bioreactor improves health of neuronal cells.

    Science.gov (United States)

    Di Loreto, Silvia; Sebastiani, Pierluigi; Benedetti, Elisabetta; Zimmitti, Vincenzo; Caracciolo, Valentina; Amicarelli, Fernanda; Cimini, Annamaria; Adorno, Domenico

    2006-01-01

    To examine whether a neuronal cell suspension can be held in vitro for a relatively short period without compromising survival rates and functionality, we have set up an experimental protocol planning 24 h of suspension culture in a rotary wall vessel (RWV) bioreactor before plating in a conventional adherent system. Apoptosis measurement and activated caspase-8, -9, and -3 detection have demonstrated that survey of the cells was not affected. The activity of major antioxidant enzymes (AOE), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT), was significantly decreased in RWV-maintained cells. A significant decrease of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) is coupled with a level of activated nuclear factor-kappaB (NF-kappaB) protein significantly lower in RVW cells than in the control. On the contrary, the level of IL-6 expression did not change between the test and the control. A significant up-regulation of growth-associated protein-43 (GAP-43), peroxisome proliferator-activated receptor-beta/delta (PPARbeta/delta), and acyl-CoA synthetase 2 (ACS2) in RWV cells has been detected. We provide the evidence that primary neuronal cells, at an early stage of development, can be maintained in a suspension condition before adherent plating. This experimental environment does not induce detrimental effects but may have an activator role, leading cells to development and maturation in a tridimensional state.

  20. Clofibric acid and gemfibrozil removal in membrane bioreactors.

    Science.gov (United States)

    Gutierrez-Macias, Tania; Nacheva, Petia Mijaylova

    2015-01-01

    The removal of two blood lipid regulators, clofibric acid (CLA) and gemfibrozil (GFZ), was evaluated using two identical aerobic membrane bioreactors with 6.5 L effective volume each. Polysulfone ultrafiltration hollow fiber membranes were submerged in the reactors. Different operating conditions were tested varying the organic load (F/M), hydraulic residence time (HRT), biomass concentration measured as total suspended solids in the mixed liquor (MLTSS) and the sludge retention time (SRT). Complete GFZ removal was obtained with F/M of 0.21-0.48 kg COD kgTSS⁻¹ d⁻¹, HRT of 4-10 hours, SRT of 10-32 d and MLTSS of 6-10 g L⁻¹. The GFZ removal can be attributed to biodegradation and there was no accumulation of the compound in the biomass. The CLA removals improved with the SRT and HRT increase and F/M decrease. Average removals of 78-79% were obtained with SRT 16-32 d, F/M of 0.21-0.34 kgCOD kgTSS⁻¹ d⁻¹, HRT of 7-10 hours and MLTSS of 6-10 g L⁻¹. Biodegradation was found to be the main removal pathway. PMID:25909723

  1. Food industrial wastewater reuse by membrane bio-reactor

    Directory of Open Access Journals (Sweden)

    Patthanant Natpinit

    2007-11-01

    Full Text Available The objective of this investigation was to study the possibility and performance of treating food industrial wastewater by Membrane BioReactor (MBR. In addition, the effluent of MBR was treated by Reverse Osmosis system (RO to reuse in boiler or cooling tower. The membranes of hollow fiber type were filled in the aerobic tank with aerobe bacteria. The total area of membrane 6 units was 630 m2 so the flux of the operation was 0.25 m/d or 150 m3/d. The spiral wound RO was operated at 100 m3/d of influent and received 72 m3/d of permeate. The sludge volume (MLSS of MBR was maintained at 8,000-10,000 mg/l. The average COD and SS of MBR influent were 600 mg/l and 300 mg/l respectively. After treating by MBR, COD and SS of effluent were maintained at less than 100 mg/l and less than 10 mg/l respectively. In the same way, COD and SS of RO permeate were less than 10 mg/l and less than 5 mg/l respectively.

  2. Mechanism of calcium mitigating membrane fouling in submerged membrane bioreactors.

    Science.gov (United States)

    Zhang, Hanmin; Xia, Jie; Yang, Yang; Wang, Zixing; Yang, Fenglin

    2009-01-01

    Two parallel membrane bioreactors (MBRs) were operated under different calcium dosages (168.5, 27 mg/L) to gain a better understanding of the mechanism of retarding membrane fouling by adding calcium. The results showed that the particle size of sludge flocs increased and the particle size distribution tended to be narrow at the optimum dosage (168.5 mg/L). Calcium was effective in decreasing loosely bound extracellular polymeric substances (LB-EPS) in microbial flocs and soluble microbial products (SMP) in the supernatant at the dosage of 168.5 mg/L by strengthening the neutralization and bridging of EPS with flocs. Furthermore, the amount of CODs and CODc decreased in both the mixed liquor and the fouling cake layer on the membrane surface. In order to compare the filtration characteristics of cake layers from the MBRs with the two calcium dosages, the specific cake resistance and the compressibility coefficient were measured. The specific cake resistance from the MBR with optimum dosage (168.5 mg/L) was distinctly lower than that with low dosage (27 mg/L). The compressibility coefficient of the cake layers under two dosages were respectively attained as 0.65, 0.91. Scanning electron microscopy (SEM) and three-dimensional confocal scanning laser microscope analysis (CLSM) images were utilized to observe the gel layer directly. PMID:19862919

  3. Fiber Treatment Effects on Bioreactor Bulk Fluid Trends

    Science.gov (United States)

    Ellis, Ronald II

    2013-01-01

    In order to facilitate the exploration of worlds beyond the borders of our planet, it is necessary to maintain sustainable levels of clean water. The remediation of water via Membrane Aerated Bioreactors (MABRs) is one such method, and the focus of this study. MARRs rely on healthy biofilms grown on hollow fiber membranes to clean non-potable water. These biofilms can take weeks to months to establish. Therefore, various fiber treatments and two inoculums were evaluated for their effect on rapid biofilm formation. Fiber treatments are as follows: sanding of the fibers with 1500 and 8000 grit sandpaper, immersion of the fibers in a 1% hydrofluoric acid solution for 12 seconds and 15 minutes, and the immersion of the fibers in a Fluoroetch® solution for 18 seconds and 5 minutes. The two inoculums utilized were sourced from healthy, established MARRs; Texas Tech University (TTU) MABR "TRL5" and Kennedy Space Center (KSC) MABR "R3". Data attained from direct bacterial cell counts of the reactor bulk fluids via fluorescent microscopy, suggests that the fluoroetching treatment combined with the TTU inoculum show the greatest biofilm creation.

  4. Characterization of effluent water qualities from satellite membrane bioreactor facilities.

    Science.gov (United States)

    Hirani, Zakir M; Bukhari, Zia; Oppenheimer, Joan; Jjemba, Patrick; LeChevallier, Mark W; Jacangelo, Joseph G

    2013-09-15

    Membrane bioreactors (MBRs) are often a preferred treatment technology for satellite water recycling facilities since they produce consistent effluent water quality with a small footprint and require little or no supervision. While the water quality produced from centralized MBRs has been widely reported, there is no study in the literature addressing the effluent quality from a broad range of satellite facilities. Thus, a study was conducted to characterize effluent water qualities produced by satellite MBRs with respect to organic, inorganic, physical and microbial parameters. Results from sampling 38 satellite MBR facilities across the U.S. demonstrated that 90% of these facilities produced nitrified (NH4-N <0.4 mg/L-N) effluents that have low organic carbon (TOC <8.1 mg/L), turbidities of <0.7 NTU, total coliform bacterial concentrations <100 CFU/100 mL and indigenous MS-2 bacteriophage concentrations <21 PFU/100 mL. Multiple sampling events from selected satellite facilities demonstrated process capability to consistently produce effluent with low concentrations of ammonia, TOC and turbidity. UV-254 transmittance values varied substantially during multiple sampling events indicating a need for attention in designing downstream UV disinfection systems. Although enteroviruses, rotaviruses and hepatitis A viruses (HAV) were absent in all samples, adenoviruses were detected in effluents of all nine MBR facilities sampled. The presence of Giardia cysts in filtrate samples of two of nine MBR facilities sampled demonstrated the need for an appropriate disinfection process at these facilities. PMID:23871258

  5. Clofibric acid and gemfibrozil removal in membrane bioreactors.

    Science.gov (United States)

    Gutierrez-Macias, Tania; Nacheva, Petia Mijaylova

    2015-01-01

    The removal of two blood lipid regulators, clofibric acid (CLA) and gemfibrozil (GFZ), was evaluated using two identical aerobic membrane bioreactors with 6.5 L effective volume each. Polysulfone ultrafiltration hollow fiber membranes were submerged in the reactors. Different operating conditions were tested varying the organic load (F/M), hydraulic residence time (HRT), biomass concentration measured as total suspended solids in the mixed liquor (MLTSS) and the sludge retention time (SRT). Complete GFZ removal was obtained with F/M of 0.21-0.48 kg COD kgTSS⁻¹ d⁻¹, HRT of 4-10 hours, SRT of 10-32 d and MLTSS of 6-10 g L⁻¹. The GFZ removal can be attributed to biodegradation and there was no accumulation of the compound in the biomass. The CLA removals improved with the SRT and HRT increase and F/M decrease. Average removals of 78-79% were obtained with SRT 16-32 d, F/M of 0.21-0.34 kgCOD kgTSS⁻¹ d⁻¹, HRT of 7-10 hours and MLTSS of 6-10 g L⁻¹. Biodegradation was found to be the main removal pathway.

  6. Residence time distributions of gas flowing through rotating drum bioreactors.

    Science.gov (United States)

    Hardin, M T; Howes, T; Mitchell, D A

    2001-07-20

    Residence time distribution studies of gas through a rotating drum bioreactor for solid-state fermentation were performed using carbon monoxide as a tracer gas. The exit concentration as a function of time differed considerably from profiles expected for plug flow, plug flow with axial dispersion, and continuous stirred tank reactor (CSTR) models. The data were then fitted by least-squares analysis to mathematical models describing a central plug flow region surrounded by either one dead region (a three-parameter model) or two dead regions (a five-parameter model). Model parameters were the dispersion coefficient in the central plug flow region, the volumes of the dead regions, and the exchange rates between the different regions. The superficial velocity of the gas through the reactor has a large effect on parameter values. Increased superficial velocity tends to decrease dead region volumes, interregion transfer rates, and axial dispersion. The significant deviation from CSTR, plug flow, and plug flow with axial dispersion of the residence time distribution of gas within small-scale reactors can lead to underestimation of the calculation of mass and heat transfer coefficients and hence has implications for reactor design and scale-up. PMID:11370003

  7. One-stage partial nitritation and anammox in membrane bioreactor.

    Science.gov (United States)

    Huang, Xiaowu; Sun, Kaihang; Wei, Qiaoyan; Urata, Kohei; Yamashita, Yuki; Hong, Nian; Hama, Takehide; Kawagoshi, Yasunori

    2016-06-01

    Partial nitritation and anammox (PN/A) was applied in a lab-scale membrane bioreactor (MBR) to investigate its technical feasibility for treating ammonium-rich wastewater with low C/N ratio. The bacterial community was analyzed by molecular cloning and 16S rRNA sequence analysis. Partial nitritation (PN) was first realized in MBR by seeding aerobic activated sludge. With dissolved oxygen control, a steady effluent mixture with NO2 (-)-N/NH4 (+)-N ratio of 1.13 ± 0.08 was generated from the PN process. Subsequently, the MBR was seeded with anammox biomass on day 59. After running 300 days, the one-stage PN/A achieved a maximum nitrogen removal rate of 1.45 kg N/m(3)/day at the nitrogen removal efficiency of 89.5 %. Microbial community analysis revealed that Nitrosomonas sp. HKU and Nitrosospira sp. YKU corresponded to nitritation; meanwhile, Candidatus Brocadia TKU sp. accounted for nitrogen removal of the PN/A system. Specifically, Nitrosomonas sp. were enriched in the reactor at the PN/A phase and then conquered Nitrosospira sp. to be the predominant ammonia oxidizers. Nitrite oxidizers and denitrifiers were detected in symbiosis with aforementioned microbes. Denitrification promised potential plus nitrogen depletion. The present one-stage PN/A process allows a significant decrease in operational costs compared with classical nitrification/denitrification. PMID:26916267

  8. 1971 : Association des Amis des Archives du Haut-Rhin

    OpenAIRE

    Eichenlaub, Jean-Luc

    2012-01-01

    Créée le 29 juin 1971, l’Association des Amis des Archives du Haut‑Rhin a été enregistrée au registre des associations du Tribunal d’Instance de Colmar le 3 août 1971 (vol. 23 N° 31). Ses statuts précisent ses buts : favoriser la connaissance des archives du Haut-Rhin et des services qu’elles rendent à l’administration et à la recherche scientifique. établir des échanges d’informations entre les chercheurs. faciliter la fréquentation des cours du service éducatif. promouvoir ou aider les acti...

  9. Full-scale demonstration of treatment of mechanically separated organic residue in a bioreactor at VAM in Wijster

    NARCIS (Netherlands)

    Oonk, H.; Woelders, H.

    1999-01-01

    At the VAM waste treatment company in Wijster a demonstration is in progress of bioreactor technology for the treatment of mechanically separated organic residue (MSOR) of a waste separation plant. This bioreactor is an in situ fermentation cell in which physical, chemical and biological processes a

  10. Dynamic Single-Use Bioreactors Used in Modern Liter- and m(3)- Scale Biotechnological Processes: Engineering Characteristics and Scaling Up.

    Science.gov (United States)

    Löffelholz, Christian; Kaiser, Stephan C; Kraume, Matthias; Eibl, Regine; Eibl, Dieter

    2014-01-01

    During the past 10 years, single-use bioreactors have been well accepted in modern biopharmaceutical production processes targeting high-value products. Up to now, such processes have mainly been small- or medium-scale mammalian cell culture-based seed inoculum, vaccine or antibody productions. However, recently first attempts have been made to modify existing single-use bioreactors for the cultivation of plant cells and tissue cultures, and microorganisms. This has even led to the development of new single-use bioreactor types. Moreover, due to safety issues it has become clear that single-use bioreactors are the "must have" for expanding human stem cells delivering cell therapeutics, the biopharmaceuticals of the next generation. So it comes as no surprise that numerous different dynamic single-use bioreactor types, which are suitable for a wide range of applications, already dominate the market today. Bioreactor working principles, main applications, and bioengineering data are presented in this review, based on a current overview of greater than milliliter-scale, commercially available, dynamic single-use bioreactors. The focus is on stirred versions, which are omnipresent in R&D and manufacturing, and in particular Sartorius Stedim's BIOSTAT family. Finally, we examine development trends for single-use bioreactors, after discussing proven approaches for fast scaling-up processes.

  11. A low-cost, multiplexable, automated flow cytometry procedure for the characterization of microbial stress dynamics in bioreactors

    DEFF Research Database (Denmark)

    Brognaux, Alison; Han, Shanshan; Sørensen, Søren Johannes;

    2013-01-01

    in order to study the dynamics of segregation directly in bioreactors. In this context, specific interfaces have been developed in order to connect a flow cytometer directly to a bioreactor for automated analyses. In this work, we propose a simplified version of such an interface and demonstrate its...

  12. GENOMIQUE ET LIPIDES Génomique et métabolisme des lipides des plantes

    Directory of Open Access Journals (Sweden)

    Delseny Michel

    2002-03-01

    Full Text Available Il existe dans les bases de données publiques une énorme quantité de séquences d’ADN dérivées de plantes, et notamment la séquence complète du génome d’Arabidopsis thaliana, une plante modèle pour les oléagineux, proche parente du colza. Ces données constituent une ressource importante non seulement pour la compréhension de métabolisme lipidique et de sa régulation, mais aussi pour la sélection et le développement de variétés nouvelles d’oléagineux produisant davantage d’huiles ou des huiles de composition nouvelle. Cette abondance de séquences peut être exploitée, en utilisant les recherches d’homologies, pour identifier les gènes, pour obtenir des informations sur leur fonction, comme pour repérer des gènes candidats codant des fonctions nouvelles. L’analyse de ces bases de données a révélé que la majeure partie des gènes codant des enzymes impliquées dans le métabolisme lipidique appartient à des petites familles multigéniques, reflétant la diversification des fonctions des isoformes. Une analyse du catalogue des ADNc séquencés en aveugle reflète les niveaux d’expression des différents gènes et fournit un aperçu des régulations des flux au travers des voies métaboliques conduisant à la biosynthèse des lipides de réserve. La disponibilité de mutants et de lignées transgéniques d’Arabidopsis et le développement de puces à ADN qui permettent l’analyse simultanée de plusieurs milliers de gènes conduiront à une meilleure compréhension des facteurs qui régulent le métabolisme des huiles dans les graines. Une telle connaissance facilitera la manipulation de la composition des huiles et des quantités produites dans les graines.

  13. La science des Sols en France

    OpenAIRE

    Pédro, Georges

    1986-01-01

    Ce rapport présente une analyse très complète de l'état de la Science des Sols en France. L'auteur traite des aspects conceptuels et structurels caractérisant cette discipline. Grâce à une démarche critique, il en envisage les perspectives de développement.

  14. Supply Chain et Gestion des ressources humaines

    OpenAIRE

    Nondonfaz, Robert

    2010-01-01

    Rappels de quelques exigences de la Supply Chain en matière de gestion des ressources humaines; spécificités de certains métiers : chauffeur, magasinier, acheteur, gestionnaire de stock, gestion des imprévus

  15. A novel milliliter-scale chemostat system for parallel cultivation of microorganisms in stirred-tank bioreactors.

    Science.gov (United States)

    Schmideder, Andreas; Severin, Timm Steffen; Cremer, Johannes Heinrich; Weuster-Botz, Dirk

    2015-09-20

    A pH-controlled parallel stirred-tank bioreactor system was modified for parallel continuous cultivation on a 10 mL-scale by connecting multichannel peristaltic pumps for feeding and medium removal with micro-pipes (250 μm inner diameter). Parallel chemostat processes with Escherichia coli as an example showed high reproducibility with regard to culture volume and flow rates as well as dry cell weight, dissolved oxygen concentration and pH control at steady states (n=8, coefficient of variation bioreactor on a liter-scale. Thus, parallel and continuously operated stirred-tank bioreactors on a milliliter-scale facilitate timesaving and cost reducing steady state studies with microorganisms. The applied continuous bioreactor system overcomes the drawbacks of existing miniaturized bioreactors, like poor mass transfer and insufficient process control.

  16. Anaerobic waste water purification and biogas production in a pulsed bioreactor. Anaerobe Abwasserreinigung mit Biogasgewinnung in einem gepulsten Bioreaktor

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, K.Y.

    1986-12-18

    The author's experiments were carried out in a novel type of bioreactor. In view of the advantages in the anaerobic process (high concentrations of biomass), the microorganisms were retained inside the bioreactor by fixation on a carrier. To avoid the problems otherwise encountered in bioreactors with fixed bacteria, in the pulsed bioreactor the block of foamed polymer carrying the bacteria is moved upwards and downwards in a single period at longer intervals of time. The reactor geometry and the pulsed movement assure a uniform and strong flow through the carrier material; gas bubbles are quickly removed from the bacterial surfaces and led out of the bioreactor, thus ensuring uniform bacterial supply and discharge. The biochemical conversion rate was determined using a highly burdened liquid filtrate waste. The conversion rate and gas productivity were found to be a function of the time of residue and room burden.

  17. Improved mass multiplication of Rhodiola crenulata shoots using temporary immersion bioreactor with forced ventilation.

    Science.gov (United States)

    Zhao, Yan; Sun, Wei; Wang, Ying; Saxena, Praveen K; Liu, Chun-Zhao

    2012-03-01

    A temporary immersion bioreactor system was found to be suitable for mass shoot proliferation of Rhodiola crenulata. The shoot multiplication ratio and hyperhydration rate reached 46.8 and 35.4%, respectively, at a temporary immersion cycle of 3-min immersion every 300 min. Forced ventilation was employed in the temporary immersion bioreactor culture in order to decrease the hyperhydration rate, improve shoot quality and enhance the multiplication ratio. The highest multiplication ratio of 55.7 was obtained under a temporary immersion cycle of 3-min immersion every 180 min with the forced ventilation at an air flow rate of 40 l/h, and the hyperhydration rate was reduced to 26.1%. Forced ventilation also improved the subsequent elongation and rooting rate of these proliferated shoots, and the shoot cultures from the temporary immersion bioreactor formed complete plantlets when subcultured onto a rooting medium containing 5 μmol/l indole-3-acetic acid. PMID:22238017

  18. Photosynthetic bacteria production from food processing wastewater in sequencing batch and membrane photo-bioreactors.

    Science.gov (United States)

    Chitapornpan, S; Chiemchaisri, C; Chiemchaisri, W; Honda, R; Yamamoto, K

    2012-01-01

    Application of photosynthetic process could be highly efficient and surpass anaerobic treatment in releasing less greenhouse gas and odor while the biomass produced can be utilized. The combination of photosynthetic process with membrane separation is possibly effective for water reclamation and biomass production. In this study, cultivation of mixed culture photosynthetic bacteria from food processing wastewater was investigated in a sequencing batch reactor (SBR) and a membrane bioreactor (MBR) supplied with infrared light. Both photo-bioreactors were operated at a hydraulic retention time (HRT) of 10 days. Higher MLSS concentration achieved in the MBR through complete retention of biomass resulted in a slightly improved performance. When the system was operated with MLSS controlled by occasional sludge withdrawal, total biomass production of MBR and SBR photo-bioreactor was almost equal. However, 64.5% of total biomass production was washed out with the effluent in SBR system. Consequently, the higher biomass could be recovered for utilization in MBR. PMID:22258682

  19. Anaerobic membrane bioreactor for the treatment of leachates from Jebel Chakir discharge in Tunisia.

    Science.gov (United States)

    Zayen, Amal; Mnif, Sami; Aloui, Fathi; Fki, Firas; Loukil, Slim; Bouaziz, Mohamed; Sayadi, Sami

    2010-05-15

    Landfill leachate (LFL) collected from the controlled discharge of Jebel Chakir in Tunisia was treated without any physical or chemical pretreatment in an anaerobic membrane bioreactor (AnMBR). The organic loading rate (OLR) in the AnMBR was gradually increased from 1 g COD l(-1)d(-1) to an average of 6.27 g COD l(-1)d(-1). At the highest OLR, the biogas production was more than 3 volumes of biogas per volume of the bioreactor. The volatile suspended solids (VSSs) reached a value of approximately 3 g l(-1) in the bioreactor. At stable conditions, the treatment efficiency was high with an average COD reduction of 90% and biogas yield of 0.46 l biogas per g COD removed. PMID:20096996

  20. Membrane Distillation Bioreactor (MDBR) - A lower Green-House-Gas (GHG) option for industrial wastewater reclamation.

    Science.gov (United States)

    Goh, Shuwen; Zhang, Jinsong; Liu, Yu; Fane, Anthony G

    2015-12-01

    A high-retention membrane bioreactor system, the Membrane Distillation Bioreactor (MDBR) is a wastewater reclamation process which has the potential to tap on waste heat generated in industries to produce high quality product water. There are a few key factors which could make MDBR an attractive advanced treatment option, namely tightening legal requirements due to increasing concerns on the micropollutants in industrial wastewater effluents as well as concerns over the electrical requirement of pressurized advanced treatment processes and greenhouse gas emissions associated with wastewater reclamation. This paper aims to provide a consolidated review on the current state of research for the MDBR system and to evaluate the system as a possible lower Green House Gas (GHG) emission option for wastewater reclamation using the membrane bioreactor-reverse osmosis (MBR-RO) system as a baseline for comparison. The areas for potential applications and possible configurations for MDBR applications are discussed.