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Four members of a homologous series of chlorinated poly(vinyl ester) oligomers CCl₃–(CH₂CH (OCO(CH₂)ₘCH₃))ₙ–Cl with degrees of polymerization of 10 and 20 were prepared by telomerisation using carbon tetrachloride. The number of side chain carbon atoms ranges from 2 (poly(vinyl acetate) to 18 (poly(vinyl stearate)). The effect of the n-alkyl side chain length and of the degree of polymerization on the thermal stability and crystallization behaviour of the synthesized compounds was investigated.
All oligomers degrade in two major steps by first losing HCl and side chains with subsequent breakdown of the backbone. The members with short side chains, up to poly(vinyl octanoate), are amorphous and show internal plasticization, whereas those with high number of side chain carbon atoms are semi-crystalline due to side-chain crystallization. A better packing for poly(vinyl stearate) is also noticeable. The glass transition and melting temperatures as well as the onset temperature of decomposition are influenced to a larger extent by the side chain length than by the degree of polymerization. Thermal stability is improved if both the size and number of side chains increase, but only a long side chain causes a significant increase of the resistance to degradation. This results in a stabilization of PVAc so that oligomers from poly(vinyl octanoate) on are stable under atmospheric conditions. Thus, the way to design stable, chlorinated PVEs oligomers is to use a long n-alkyl side chain.
Sensitivity of turbulent Schmidt number and turbulence model to simulations of jets in crossflow
(2016)
Environmental discharges have been traditionally designed by means of cost-intensive and time-consuming experimental studies. Some extensively validated models based on an integral approach have been often employed for water quality problems, as recommended by USEPA (i.e.: CORMIX). In this study, FLOW-3D is employed for a full 3D RANS modelling of two turbulent jet-to-crossflow cases, including free surface jet impingement. Results are compared to both physical modelling and CORMIX to better assess model performance. Turbulence measurements have been collected for a better understanding of turbulent diffusion's parameter sensitivity. Although both studied models are generally able to reproduce jet trajectory, jet separation downstream of the impingement has been reproduced only by RANS modelling. Additionally, concentrations are better reproduced by FLOW-3D when the proper turbulent Schmidt number is used. This study provides a recommendation on the selection of the turbulence model and the turbulent Schmidt number for future outfall structures design studies.
The performance and biomass yield of the perennial energy plant Sida hermaphrodita (hereafter referred to as Sida) as a feedstock for biogas and solid fuel was evaluated throughout one entire growing period at agricultural field conditions. A Sida plant development code was established to allow comparison of the plant growth stages and biomass composition. Four scenarios were evaluated to determine the use of Sida biomass with regard to plant development and harvest time: (i) one harvest for solid fuel only; (ii) one harvest for biogas production only; (iii) one harvest for biogas production, followed by a harvest of the regrown biomass for solid fuel; and (iv) two consecutive harvests for biogas production. To determine Sida's value as a feedstock for combustion, we assessed the caloric value, the ash quality, and melting point with regard to DIN EN ISO norms. The results showed highest total dry biomass yields of max. 25 t ha⁻¹, whereas the highest dry matter of 70% to 80% was obtained at the end of the growing period. Scenario (i) clearly indicated the highest energy recovery, accounting for 439 288 MJ ha⁻¹; the energy recovery of the four scenarios from highest to lowest followed this order: (i) ≫ (iii) ≫ (iv) > (ii). Analysis of the Sida ashes showed a high melting point of >1500 °C, associated with a net calorific value of 16.5–17.2 MJ kg⁻¹. All prerequisites for DIN EN ISO norms were achieved, indicating Sida's advantage as a solid energy carrier without any post-treatment after harvesting. Cell wall analysis of the stems showed a constant lignin content after sampling week 16 (July), whereas cellulose had already reached a plateau in sampling week 4 (April). The results highlight Sida as a promising woody, perennial plant, providing biomass for flexible and multipurpose energy applications.
Autoradiography is a well-established method of nuclear imaging. When different radionuclides are present simultaneously, additional processing is needed to distinguish distributions of radionuclides. In this work, a method is presented where aluminium absorbers of different thickness are used to produce images with different cut-off energies. By subtracting images pixel-by-pixel one can generate images representing certain ranges of β-particle energies. The method is applied to the measurement of irradiated reactor graphite samples containing several radionuclides to determine the spatial distribution of these radionuclides within pre-defined energy windows. The process was repeated under fixed parameters after thermal treatment of the samples. The greyscale images of the distribution after treatment were subtracted from the corresponding pre-treatment images. Significant changes in the intensity and distribution of radionuclides could be observed in some samples. Due to the thermal treatment parameters the most significant differences were observed in the ³H and ¹⁴C inventory and distribution.
Self-aeration is traditionally explained by the water turbulent boundary layer outer edge intersection with the free surface. This paper presents a discussion on the commonly accepted hypothesis behind the computation of the critical point of self-aeration in spillway flows and a new formulation is proposed based on the existence of a developing air flow over the free surface. Upstream of the inception point of self-aeration, some surface roughening has been often reported in previous studies which consequently implies some entrapped air transport and air–water flows coupling. Such air flow is proven in this study by presenting measured air velocities and computing the air boundary layer thickness for a 1V:2H smooth chute flow. Additionally, the growth rate of free surface waves has been analysed by means of Ultrasonic Sensors measurements, obtaining also the entrapped air concentration. High-speed camera imaging has been used for qualitative study of the flow perturbations.
An amperometric biosensor using a substrate recycling principle was realized for the detection of low adrenaline concentrations (1 nM) by measurements in phosphate buffer and Ringer’s solution at pH 6.5 and pH 7.4, respectively. In proof-of-concept experiments, a Boolean logic-gate principle has been applied to develop a digital adrenaline biosensor based on an enzyme AND logic gate. The obtained results demonstrate that the developed digital biosensor is capable for a rapid qualitative determination of the presence/absence of adrenaline in a YES/NO statement. Such digital biosensor could be used in clinical diagnostics for the control of a correct insertion of a catheter in the adrenal veins during adrenal venous-sampling procedure.
Purpose
The most commonly used mobility assessments for screening risk of falls among older adults are rating scales such as the Tinetti performance oriented mobility assessment (POMA). However, its correlation with falls is not always predictable and disadvantages of the scale include difficulty to assess many of the items on a 3-point scale and poor specificity. The purpose of this study was to describe the ability of the new Aachen Mobility and Balance Index (AMBI) to discriminate between subjects with a fall history and subjects without such events in comparison to the Tinetti POMA Scale.
Methods
For this prospective cohort study, 24 participants in the study group and 10 in the control group were selected from a population of patients in our hospital who had met the stringent inclusion criteria. Both groups completed the Tinetti POMA Scale (gait and balance component) and the AMBI (tandem stance, tandem walk, ten-meter-walk-test, sit-to-stand with five repetitions, 360° turns, timed-up-and-go-test and measurement of the dominant hand grip strength). A history of falls and hospitalization in the past year were evaluated retrospectively. The relationships among the mobility tests were examined with Bland–Altmananalysis. Receiver-operated characteristics curves, sensitivity and specificity were calculated.
Results
The study showed a strong negative correlation between the AMBI (17 points max., highest fall risk) and Tinetti POMA Scale (28 points max., lowest fall risk; r = −0.78, p < 0.001) with an excellent discrimination between community-dwelling older people and a younger control group. However, there were no differences in any of the mobility and balance measurements between participants with and without a fall history with equal characteristics in test comparison (AMBI vs. Tinetti POMA Scale: AUC 0.570 vs. 0.598; p = 0.762). The Tinetti POMA Scale (cut-off <20 points) showed a sensitivity of 0.45 and a specificity of 0.69, the AMBI a sensitivity of 0.64 and a specificity of 0.46 (cut-off >5 points).
Conclusion
The AMBI comprises mobility and balance tasks with increasing difficulty as well as a measurement of the dominant hand-grip strength. Its ability to identify fallers was comparable to the Tinetti POMA Scale. However, both measurement sets showed shortcomings in discrimination between fallers and non-fallers based on a self-reported retrospective falls-status.
The light-addressable potentiometric sensor (LAPS) has the unique feature to address different regions of a sensor surface without the need of complex structures. Measurements at different locations on the sensor surface can be performed in a common analyte solution, which distinctly simplifies the fluidic set-up. However, the measurement in a single analyte chamber prevents the application of different drugs or different concentrations of a drug to each measurement spot at the same time as in the case of multi-reservoir-based set-ups. In this work, the authors designed a LAPS-based set-up for cell culture screening that utilises magnetic beads loaded with the endotoxin (lipopolysaccharides, LPS), to generate a spatially distributed gradient of analyte concentration. Different external magnetic fields can be adjusted to move the magnetic beads loaded with a specific drug within the measurement cell. By recording the metabolic activities of a cell layer cultured on top of the LAPS surface, this work shows the possibility to apply different concentrations of a sample along the LAPS measurement spots within a common analyte solution.
Light-addressable potentiometric sensor as a sensing element in plug-based microfluidic devices
(2016)
A plug-based microfluidic system based on the principle of the light-addressable potentiometric sensor (LAPS) is proposed. The LAPS is a semiconductor-based chemical sensor, which has a free addressability of the measurement point on the sensing surface. By combining a microfluidic device and LAPS, ion sensing can be performed anywhere inside the microfluidic channel. In this study, the sample solution to be measured was introduced into the channel in a form of a plug with a volume in the range of microliters. Taking advantage of the light-addressability, the position of the plug could be monitored and pneumatically controlled. With the developed system, the pH value of a plug with a volume down to 400 nL could be measured. As an example of plug-based operation, two plugs were merged in the channel, and the pH change was detected by differential measurement.
Neben dem durch Unfälle und Krankheiten entstehenden menschlichen Leids und der daraus resultierenden moralischen Verpflichtung, sich und seine Mitmenschen vor Schaden zu bewahren, ist der Arbeits- und Gesundheitsschutz auch ein Gebot wirtschaftlichen Handelns, da Arbeitsunfälle und Berufskrankheiten Ausfallzeiten und Kosten verursachen. So gehören Arbeits- und Gesundheitsschutz zu den wichtigen Aufgaben eines Unternehmens.
Kalkulation
(2016)
Das Kapitel behandelt die Kosten- und Preisermittlung, die Kostenvorgabe und Kostenkontrolle.
Der Angebotspreis wird aufgeschlüsselt in die Einzelkosten der Teilleistungen, die Baustellengemeinkosten, die Allgemeinen Geschäftskosten und einen Zuschlag für Wagnis und Gewinn. Auf der Basis der Angebotskalkulation werden die Vorgaben für die Kostenkontrolle entwickelt.
Betriebsorganisation
(2016)
Das Kapitel behandelt, ausgehend von Begriffen und Aufgaben der Betriebsorganisation, die Aufbau- und Ablauforganisation der Bauunternehmung sowie die Gestaltung einer Projekt-organisation. Es folgt eine Darstellung der Managementsysteme für Qualität, Umwelt und Arbeitsschutz, die sich zunehmend als sog. integrierte Managementsysteme (IMS) auch in Bauunternehmen etablieren. Grundlagen des Personalmanagements und des betrieblichen Rechnungswesens, die für eine(n) Baubetriebler(in) relevant sein können, ergänzen das Kap. Betriebsorganisation. Den Abschluss bilden Hinweise zum Berichtswesen der Baustelle.
Schalung und Gerüste
(2016)
Systemschalungen und Systemgerüste haben den Baustellenbetrieb in vielen Bereichen sehr vereinfacht. Dennoch sind Kenntnisse in diesen Feldern für eine erfolgreiche und effektive Bauleitung unverzichtbar. In diesem Kapitel werden Hinweise und Empfehlungen für die Bemessung und Einsatz von Schalungen, Trag- und Arbeitsgerüsten für den Baustellenbetrieb gegeben.
Boden, Baugrube, Verbau
(2016)
Die Lösung den Baugrund betreffender Fragestellungen beginnen i. d. R. mit der Durchführung von Baugrunderkundungen, um alle notwendigen Parameter zu erhalten, die für die Planung und Durchführung von Bauvorhaben notwendig sind. Im Folgenden werden die wichtigsten Erkundungen in Abhängigkeit der erforderlichen Güteklasse der Proben beschrieben und vorgestellt.
Baumaschinen
(2016)
Kosten- und Verfahrensvergleiche können dabei zur Ermittlung des für die Aufgabe geeignetsten Bauverfahren führen. Für die sich daran anschließende Ablaufplanung werden die verschiedenen graphischen sowie rechnerischen Instrumente (Terminliste und Taktplan, Balkenplan, Weg-Zeit-Diagramm und Netzplan) erläutert und anhand von Beispielen vertieft. Schließlich wird ein im Rahmen der Arbeits- und Nachkalkulation vorzunehmender Soll-Ist-Vergleich mit Hilfe des Bauarbeitsschlüssels (BAS) zur Überprüfung der Aufwands- und Leistungswerte dargestellt.
In diesem Kapitel werden die Abrechnungsvorschriften wichtiger ATV kurz, aber umfassend zusammengestellt. Einigen Abrechnungsbestimmungen für Einzelleistungen, die keine Nebenleistungen sind ((siehe DIN 18299 und Abschnitt 4 der jeweiligen ATV), sind mit aufgenommen worden; die ATV enthalten jedoch weitergehende Festlegungen über Nebenleistungen und Besondere Leistungen.
Im Anschluss folgen Hinweise zu den Toleranzen im Hochbau sowie im Straßenbau.
Das Gesetz gegen Wettbewerbsbeschränkungen bildet die Grundlage für die Verordnung über die Vergabe öffentlicher Aufträge, aus der sich die Vergabe- und Vertragsordnungen für Freiberufliche Leistungen (VOF), für Lieferungen und Leistungen (VOL) und für Bauleistungen (VOB) ableiten. Die dabei in Frage kommenden Vergabeverfahren und die einzelnen Schwellenwerte gemäß EU-Recht werden detailliert aufbereitet und im Zusammenhang dargestellt.
Die für die Ausgestaltung von Bauverträgen notwendigen Grundlagen des Werkvertragsrecht nach BGB sowie die branchenspezifischen Allgemeinen Geschäftsbedingungen in Form der Vertragsordnung für Bauleistungen (VOB) mit ihren Zusätzlichen und Besonderen Vertragsbedingungen werden intensiv aufbereitet. Das Zustandekommen eines Bauvertrages ergibt sich dann aus der notwendigen Leistungsbeschreibung mit einem Leistungsverzeichnis und verschiedenen Positionen oder in Form einer Funktionalen Leistungsbeschreibung (Beschreibung mit Leistungsprogramm).
Das Auslandsgeschäft der Baubranche (Bauausführende Unternehmen sowie Beratende Ingenieure und Consultants) wird von den jeweils vorliegenden Internationalen Wettbewerbsbedingungen bestimmt, deren Zusammenhänge anhand umfangreicher statistischer Daten und anhand von Beispielen dargestellt werden.
Baukosten und Finanzierung
(2016)
Bauwirtschaft und Baurecht
(2016)
Die Leistungen der Bauwirtschaft und deren wirtschaftliche Bedeutung in Deutschland werden anhand einer Vielzahl statistischer Daten verdeutlicht. Die im Vergleich zu anderen Wirtschaftsbereichen auftretenden branchenspezifischen Besonderheiten der Bauwirtschaft werden anhand von verschiedenen Kriterien herausgearbeitet. Das Zusammenspiel der einzelnen Akteure des Sektors und die dabei sich ergebenden bzw. zu beachtenden Rechts- und Vertragsgrundlagen werden dargestellt. Aufgrund der meist erheblichen Höhe des eingesetzten Kapitals aufseiten der Auftraggeber, aber auch seitens der Bauunternehmen während der Bauausführung sowie der besonderen Verantwortung der Beratenden Ingenieure werden auch notwendige Formen der Risikoabsicherungen und der in der Branche üblichen und teilweise vorgeschriebenen Versicherungsmöglichkeiten angesprochen. Intensive Beachtung finden auch die Auswirkungen des Öffentlichen Baurechts (Baugesetzbuch, Bauordnung NRW, Baunutzungsverordnung) auf Planung, Bau und Betrieb baulicher Anlagen und der dabei verwendeten Bauprodukte.
Vermessung
(2016)
Größen, Formeln, Bemessung
(2016)
Das Kapitel 1 vermittelt eine Übersicht für den schnellen Gebrauch von Größen, Einheiten und Zeichen. Es folgt die Darstellung wichtiger Grundlagen der Mathematik, Lastannahmen und einfacher statischer Systeme. Schließlich werden Hinweise zu charakteristischen Festigkeiten und Tragfähigkeitsnachweisen für Berechnungen im Mauerwerk, Holz- und Stahlbau sowie Stahlbetonbau gegeben. Für eine weitere Vertiefung des Themas empfiehlt sich der Wendehorst Bautechnische Zahlentafel
While plate fixation of proximal ulna fractures might lead to superior clinical results compared to tension band wiring, regular plates represent an established risk factor for wound complications. The olecranon double plates (Medartis, Basel, CH) might decrease complications related to the osteosynthesis because of their low profile and better anatomical fit. This study aimed to evaluate the biomechanical performance and clinical results of the olecranon double plates.
Surgical reconstruction of the interosseous membrane (IOM) could restore longitudinal forearm stability to avoid persisting disability due to capituloradial and ulnocarpal impingement in Essex Lopresti lesions. This biomechanical study aimed to assess longitudinal forearm stability of intact specimens, after sectioning of the IOM and after reconstruction with a TightRope construct using either a single or double bundle technique.
Treatment of posttraumatic osteoarthritis of the radial column of the elbow joint remains a challenging yet common issue.
While partial joint replacement leads to high revision rates, radial head excision has shown to severely increase joint instability. Shortening osteotomy of the radius could be an option to decrease the contact pressure of the radiohumeral joint and thereby pain levels without causing valgus instability. Hence, the aim of this biomechanical study was to evaluate the effects of radial shortening on axial load distribution and valgus stability of the elbow joint.
Plate osteosynthesis of displaced proximal phalangeal neck fractures of the hand allows early mobilization due to a stable internal fixation. Nevertheless, joint stiffness—because of soft tissue irritation—represents a common complication leading to high complication rates. Del Pinal et al. recently reported promising clinical results for a new, minimally invasive fixation technique with a cannulated headless intramedullary compression screw. Hence, the aim of this study was to compare plate fixation of proximal phalangeal neck fractures to less two less invasive techniques: Crossed k-wire fixation and intramedullary screw fixation. We hypothesized that these fixation techniques provide inferior stability when compared to plate osteosynthesis.
Insolvenzanfechtung: Keine Gläubigerbenachteiligung bei Ablösezahlung gegen Forderungsverzicht
(2016)
Schwerpunkt einer vorinsolvenzlichen Sanierung ist i.d.R., dass einzelne Gläubiger gegen Teilzahlungen auf ihre Forderungen verzichten und somit dem Unternehmen den notwendigen finanziellen Freiraum für einen Turnaround geben. Die Motivation der Gläubiger für einen Verzicht ist dabei auch die Überlegung, dass eine quotale Befriedigung im Rahmen eines Insolvenzverfahrens oft wesentlich geringer ausfallen würde als die durch den Vergleich realisierte Teilzahlung. Das Risiko, im Falle der Insolvenz eine Teilzahlung im Rahmen der Insolvenzanfechtung aber wieder zurückgewähren zu müssen, macht einen Forderungsverzicht weniger attraktiv. Mit Urteil vom 28.01.2016 hat der BGH nun entschieden, dass eine Insolvenzanfechtung mangels Gläubigerbenachteiligung ausscheidet, wenn der in der Teilzahlung liegende Vermögensverlust durch den damit verbundenen Verzicht auf die Restforderung voll ausgeglichen wird. Im Folgenden wird untersucht, ob dieses Urteil als Blaupause für eine anfechtungsfeste Restrukturierung einzelner Verbindlichkeiten dienen kann.
The human arm consists of the humerus (upper arm), the medial ulna and the lateral radius (forearm). The joint between the humerus and the ulna is called humeroulnar joint and the joint between the humerus and the radius is called humeroradial joint. Lateral and medial collateral ligaments stabilize the elbow. Statistically, 2.5 out of 10,000 people suffer from radial head fractures [1]. In these fractures the cartilage is often affected. Caused by the injured cartilage, degenerative diseases like posttraumatic arthrosis may occur. The resulting pain and reduced range of motion have an impact on the patient’s quality of life. Until now, there has not been a treatment which allows typical loads in daily life activities and offers good long-term results. A new surgical approach was developed with the motivation to reduce the progress of the posttraumatic arthrosis. Here, the radius is shortened by 3 mm in the proximal part [2]. By this means, the load of the radius is intended to be reduced due to a load shift to the ulna. Since the radius is the most important stabilizer of the elbow it has to be confirmed that the stability is not affected. In the first test (Fig. 1 left), pressure distributions within the humeroulnar and humeroradial joints a native and a shortened radius were measured using resistive pressure sensors (I5076 and I5027, Tekscan, USA). The humerus was loaded axially in a tension testing machine (Z010, Zwick Roell, Germany) in 50 N steps up to 400 N. From the humerus the load is transmitted through both the radius and the ulna into the hand which is fixed on the ground. In the second test (Fig. 1 right), the joint stability was investigated using a digital image correlation system to measure the displacement of the ulna. Here, the humerus is fixed with a desired flexion angle and the unconstrained forearm lies on the ground. A rope connects the load actuator with a hook fixed in the ulna. A guide roller is used so that the rope pulls the ulna horizontally when a tensile load is applied. This creates a moment about the elbow joint with a maximum value of 7.5 Nm. Measurements were performed with varying flexion angles (0°, 30°, 60°, 90°, 120°). For both tests and each measurement, seven specimens were used. Student ́s t-test was employed to determine whether the mean values of the measurements in native specimen and operated specimens differ significantly.
The structure of the female pelvic floor (PF) is an inter-related system of bony pelvis,muscles, pelvic organs, fascias, ligaments, and nerves with multiple functions. Mechanically, thepelvic organ support system are of two types: (I) supporting system of the levator ani (LA) muscle,and (II) the suspension system of the endopelvic fascia condensation [1], [2]. Significantdenervation injury to the pelvic musculature, depolimerization of the collagen fibrils of the softvaginal hammock, cervical ring and ligaments during pregnancy and vaginal delivery weakens thenormal functions of the pelvic floor. Pelvic organ prolapse, incontinence, sexual dysfunction aresome of the dysfunctions which increases progressively with age and menopause due toweakened support system according to the Integral theory [3]. An improved 3D finite elementmodel of the female pelvic floor as shown in Fig. 1 is constructed that: (I) considers the realisticsupport of the organs to the pelvic side walls, (II) employs the improvement of our previous FEmodel [4], [5] along with the patient based geometries, (III) incorporates the realistic anatomy andboundary conditions of the endopelvic (pubocervical and rectovaginal) fascia, and (IV) considersvarying stiffness of the endopelvic fascia in the craniocaudal direction [3]. Several computationsare carried out on the presented computational model with healthy and damaged supportingtissues, and comparisons are made to understand the physiopathology of the female PF disorders.
Purpose
Two semi-empirical models were recently published, both making use of existing literature data, but each taking into account different physical phenomena that trigger hemolysis. In the first model, hemoglobin (Hb) release is described as a permeation procedure across the membrane, assuming a shear stress-dependent process (sublethal model). The second model only accounts for hemoglobin release that is caused by cell membrane breakdown, which occurs when red blood cells (RBC) undergo mechanically induced shearing for a period longer than the threshold time (nonuniform threshold model). In this paper, we introduce a model that considers the hemolysis generated by both these possible phenomena.
Methods
Since hemolysis can possibly be caused by permeation of hemoglobin through the RBC functional membrane as well as by release of hemoglobin from RBC membrane breakdown, our proposed model combines both these models. An experimental setup consisting of a Couette device was utilized for validation of our proposed model.
Results
A comparison is presented between the damage index (DI) predicted by the proposed model vs. the sublethal model vs. the nonthreshold model and experimental datasets. This comparison covers a wide range of shear stress for both human and porcine blood. An appropriate agreement between the measured DI and the DI predicted by the present model was obtained.
Conclusions
The semiempirical hemolysis model introduced in this paper aims for significantly enhanced conformity with experimental data. Two phenomenological outcomes become possible with the proposed approach: an estimation of the average time after which cell membrane breakdown occurs under the applied conditions, and a prediction of the ratio between the phenomena involved in hemolysis.
Abstractauthoren Graphene oxide (GO) nanoparticles were incorporated in temperature-sensitive Poly(N-isopropylacrylamide) (PNIPAAm) hydrogels. The nanoparticles increase the light absorption and convert light energy into heat efficiently. Thus, the hydrogels with GO can be stimulated spatially resolved by illumination as it was demonstrated by IR thermography. The temporal progression of the temperature maximum was detected for different concentrations of GO within the polymer network. Furthermore, the compatibility of PNIPAAm hydrogels with GO and cell cultures was investigated. For this purpose, culture medium was incubated with hydrogels containing GO and the viability and morphology of chinese hamster ovary (CHO) cells was examined after several days of culturing in presence of this medium.
On-line monitoring of the metabolic activity of microorganisms involved in intermediate stages of biogas production plays an important role to avoid undesirable “down times” during the biogas production. In order to control this process, an on-chip differential measuring system based on the light-addressable potentiometric sensor (LAPS) principle combined with a 3D-printed multi-chamber structure has been realized. As a test microorganism, Escherichia coli K12 (E. coli K12) were used for cell-based measurements. Multi-chamber structures were developed to determine the metabolic activity of E. coli K12 in suspension for a different number of cells, responding to the addition of a constant or variable amount of glucose concentrations, enabling differential and simultaneous measurements.
Visualization of the recovery process of defects in a cultured cell layer by chemical imaging sensor
(2016)
The chemical imaging sensor is a field-effect sensor which is able to visualize both the distribution of ions (in LAPS mode) and the distribution of impedance (in SPIM mode) in the sample. In this study, a novel cell assay is proposed, in which the chemical imaging sensor operated in SPIM mode is applied to monitor the recovery of defects in a cell layer brought into proximity of the sensing surface. A reduced impedance at a defect formed artificially in a cell layer was successfully visualized in a photocurrent image. The cell layer was cultured over two weeks, during which the temporal change of the photocurrent distribution corresponding to the recovery of the defect was observed.
A comparative performance analysis of the CFD platforms OpenFOAM and FLOW-3D is presented, focusing on a 3D swirling turbulent flow: a steady hydraulic jump at low Reynolds number. Turbulence is treated using RANS approach RNG k-ε. A Volume Of Fluid (VOF) method is used to track the air–water interface, consequently aeration is modeled using an Eulerian–Eulerian approach. Structured meshes of cubic elements are used to discretize the channel geometry. The numerical model accuracy is assessed comparing representative hydraulic jump variables (sequent depth ratio, roller length, mean velocity profiles, velocity decay or free surface profile) to experimental data. The model results are also compared to previous studies to broaden the result validation. Both codes reproduced the phenomenon under study concurring with experimental data, although special care must be taken when swirling flows occur. Both models can be used to reproduce the hydraulic performance of energy dissipation structures at low Reynolds numbers.
Im Jahr 2015 wurden in Deutschland über drei Millionen Benzinautos und lediglich 12.363 Elektroautos neu zugelassen. Das ursprünglich von der Bundesregierung vorgegebene Ziel, dass bis 2020 eine Million E-Autos auf deutschen Straßen fahren (und bis 2030 sechs Millionen), rückt damit in immer weitere Ferne. Um das Ziel dennoch zu erreichen, plant die Bundesregierung nun eine staatliche Prämie für den Kauf von Elektroautos: Umwelt-, Verkehrs- und Wirtschaftsministerium haben gemeinsam ein Konzept entworfen, dem zufolge private Käufer zukünftig einen Zuschuss von 5.000 Euro beim Erwerb eines Elektroautos bekommen sollen. 40 Prozent dieses Zuschusses soll von den Autoherstellern getragen werden. Das Programm, das weitere ausgabenwirksame öffentliche Maßnahmen vorsieht, würde Kosten in Milliardenhöhe verursachen. Die beabsichtigte Subventionierung wirft die Frage auf, ob diese wirtschaftlich sinnvoll sind.