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The miniaturized Mössbauer-spectrometer (MIMOS II), originally devised by Göstar Klingelhöfer, is further developed by the Renz group at the Leibniz University Hanover in cooperation with the Hanover University of Applied Sciences and Arts. A new processing unit with a two-dimensional (2D) data acquisition was developed by M. Jahns. The advantage of this data acquisition is that no thresholds need to be set before the measurement. The energy of each photon is determined and stored with the velocity of the drive. After the measurement, the relevant area can be selected for the Mössbauer spectrum. Now we have expanded the evaluation unit with a power supply for a MIMOS drive and a MIMOS PIN detector. So we have a very compact MIMOS transmissions measurement setup. With this setup it is possible to process the signals of two detectors serially. Currently we are working on a parallel signal processing.
This paper proposes an extended Petri net formalism as a suitable language for composing optimal scheduling problems of industrial production processes with real and binary decision variables. The proposed approach is modular and scalable, as the overall process dynamics and constraints can be collected by parsing of all atomic elements of the net graph. To conclude, we demonstrate the use of this framework for modeling the moulding sand preparation process of a real foundry plant.
HOXA9 and MEIS1 are frequently upregulated in acute myeloid leukemia (AML), including those with MLL‐rearrangement. Because of their pivotal role in hemostasis, HOXA9 and MEIS1 appear non‐druggable. We, thus, interrogated gene expression data of pre‐leukemic (overexpressing Hoxa9) and leukemogenic (overexpressing Hoxa9 and Meis1; H9M) murine cell lines to identify cancer vulnerabilities. Through gene expression analysis and gene set enrichment analyses, we compiled a list of 15 candidates for functional validation. Using a novel lentiviral multiplexing approach, we selected and tested highly active sgRNAs to knockout candidate genes by CRISPR/Cas9, and subsequently identified a H9M cell growth dependency on the cytosolic phospholipase A2 (PLA2G4A). Similar results were obtained by shRNA‐mediated suppression of Pla2g4a. Remarkably, pharmacologic inhibition of PLA2G4A with arachidonyl trifluoromethyl ketone (AACOCF3) accelerated the loss of H9M cells in bulk cultures. Additionally, AACOCF3 treatment of H9M cells reduced colony numbers and colony sizes in methylcellulose. Moreover, AACOCF3 was highly active in human AML with MLL rearrangement, in which PLA2G4A was significantly higher expressed than in AML patients without MLL rearrangement, and is sufficient as an independent prognostic marker. Our work, thus, identifies PLA2G4A as a prognostic marker and potential therapeutic target for H9M‐dependent AML with MLL‐rearrangement.
A novel method has been implemented to prepare metal oxide nanopowders covered with known quantities of adsorbed water; we subsequently studied the γ-radiolysis of ZrO2 nanopowders covered with H2O layers. H2 yields from the adsorbed water radiolysis are of importance in multiple industrial contexts – the nuclear industry being a prime example. Measured H2 yields at water coverages of just below and above one monolayer are around 350 times greater than for neat water, but these yields decrease rapidly with increasing water loading of the ZrO2 nanoparticles, approaching the yield of bulk water at coverages of tens of water layers. The observed plateau of the yields at 0.5 to 2.0 monolayers coverage can be explained by the ease with which electronic excitations in the ZrO2 can be transferred across the interface to the first one or two adsorbed water layers. However, with increasing water loading, energy transfer to water layers further away from the interface becomes less efficient, and above ~30 water layers, most of the water is not affected by any exciton formation in the ZrO2.
A new type of rotary compressor, called “rotary-chamber compressor”, consists of two interlocking rotors with 4 wings each, that perform non-uniform rotary movements. Both rotors have the same direction of rotation, while one rotor is accelerating, the other rotor is retarding. After surpassing a specific mark, the sequence changes and the leading rotor begins to retard and vice versa. Due to the resulting relative phase difference, the volume between the two wings is changing periodically, which allows pulsating working chambers. The technology was first introduced by its founder Jürgen Schukey in 1987. Since then, no further development on this machine is known to us except our own. In this contribution, a study on the kinematics of the rotary-chamber-compressor is presented. Initial studies have shown that changes in the kinematics of the rotors will have a direct influence on the thermodynamical variables, which, if optimized, can lead to an increased performance of the machine. Therefore, a mathematical model has been developed to obtain the performance parameters from different kinematic concepts by using numerical CFD analysis. Furthermore, additional optimization possibilities will be listed and discussed.
In diesem Beitrag wird die Möglichkeit dargestellt, wie Belastungsspitzen beim Betrieb von Flussturbinen in Inselnetzen durch die kinetische Energie des Wassers abgedeckt werden können. Als Beispiel dienen dabei Kühlgeräte für Lebensmittel. Flussturbinen arbeiten ohne Staustufen in der Strömung der Flüsse. Sie stellen eine Möglichkeit zur Energieversorgung von kleinen Siedlungen ohne öffentliche Stromversorgung dar. Der besondere Vorteil ist, dass sie ohne aufwändige Bauwerke zur Wasserführung auskommen.
Bei der Versorgung von Inselnetzen muss die Turbine alleine die benötigte Leistung bereitstellen. Dies gilt auch für die Abdeckung von Belastungsspitzen. In diesem Beitrag wird anhand von Beispielrechnen dargestellt, welches Potenzial die kinetische Energie des Wassers in der Turbine hat, um die Belastungsspitzen abzudecken. Die Berechnungen an Kühlgeräten zeigen, dass das Einschalten der Kühlaggregate ein kritischer Betriebspunkt beim Betrieb von Flussturbinen in Inselnetzen sein kann. Dies gilt besonders dann, wenn die stationäre Leistung bereits nahe an der verfügbaren Leistung ist.
Hier muss in recht kurzer Zeit eine große elektrische Arbeit zur Verfügung gestellt werden, die Leistung also in kurzer Zeit ansteigen und anschließend wieder abfallen. Die Abschätzung der elektrischen Arbeit, die sich aus der kinetischen Energie des Wassers in der Turbine gewinnen lässt, zeigt aber, dass durch Absenken der Fließgeschwindigkeit kurzfristig die benötigte elektrische Leistung und Arbeit bereit gestellt werden kann.
Nitric oxide adsorption on a Au(100) single crystal has been investigated to identify the type of adsorption, the adsorption site, and the orientation and alignment of the adsorbed NO relative to the surface. This was done using a combination of 3D-surface velocity map imaging, near-ambient pressure X-ray photoelectron spectroscopy, and density functional theory. NO was observed to be molecularly adsorbed on gold at ~200 K. Very narrow angular distributions and cold rotational distributions of photodesorbed NO indicate that NO adsorbs on high-symmetry sites on the Au crystal, with the N–O bond axis close to the surface normal. Our density functional theory calculations show that NO preferentially adsorbs on the symmetric bridge (2f) site, which ensures efficient overlap of the NO π* orbital with the orbitals on the two neighbouring Au atoms, and with the N–O bond axis aligned along the surface normal, in agreement with our conclusions from the rotational state distributions. The combination of XPS, which reveals the orientation of NO on gold, with 3D-surface velocity map imaging and density functional theory thus allowed us to determine the adsorption site, orientation and alignment of nitric oxide adsorbed on Au(100).
Fenster versorgen die Innenräume mit Tageslicht, dienen der Lufterneuerung in den Räumen und schützen vor Umwelteinflüssen wie Kälte, Wärme, Lärm, Wind und Niederschlägen. Entsprechend weitgefächert ist das Spektrum deer planungsrelevanten Aspekte. Sowohl licht-, lüftungs-, wärme-, schall und wohntechnische als auch hygienische, psychologische und nicht zuletzt wirtschaftliche Gesichtspunkte sind bei edr täglichen Arbeit zu beachten.
Die in den Betrieben häufig mit hohem gerätetechnischen und organisatorischem Aufwand installierten EDV-gestützten Informationssysteme zur Planung und Steuerung des Fertigungsprozesses genügen im allgemeinen nicht den an sie gestellten Anforderungen. Die Gründe dafür liegen in der Hauptsache in einem falschen Modellansatz und der mangelnden Datenqualität der eingesetzten Daten, verbunden mit einer unzureichenden Rückkopplung zwischen Vorgabe und Rückmeldung. Hinzu kommen das Fehlen geeigneter Aussagen (Kenngrößen) zur gezielten Beeinflussung des Prozesses und Akzeptanzprobleme der Mitarbeiter beim Umgang mit der EDV. Die genannten Schwachstellen geben die Richtung der Zielsetzung dieser Arbeit vor. Dieses Ziel bestand zunächst darin, eine Methode zu entwickeln, mit der die Anforderungen an die in einem Industriebetrieb zur Planung, Steuerung und Überwachung verwendeten Daten zu formulieren sind, um dann eine anforderungsgerechte Abstimmung dieser Daten im betrieblichen Datenfluß im Sinne eines kybernetischen Regelkreises vorzunehmen und Aussagen über die betrieblichen Zielgrößen zu erhalten. Aus der Vielzahl betrieblicher Vorgänge und Funktionsbereiche wurde der Fertigungsprozeß bei der Werkstättenfertigung im Produktionsbetrieb deshalb ausgewählt, weil hier in der Praxis wegen der Komplexität der Abläufe die höchsten Anforderungen an die Daten gestellt werden und deshalb auch die meisten Probleme bei der Erfüllung dieser Anforderungen auftreten. Außerdem ist die Fertigung nach dem Werkstättenprinzip am häufigsten in der Praxis anzutreffen. Als erstes war es nötig, die zeitlichen, quantitativen und qualitativen Anforderungen an die Daten aus einer Vielzahl durchgeführter Schwachstellenanalysen herauszuarbeiten und zu definieren. Die nächste Aufgabe bestand darin, die Einflußgrößen auf die Datenanforderungen, hier unterteilt in innere (datumsbezogene) und äußere (prozeßbezogene) zu bestimmen und in ihren Auswirkungen zu untersuchen. Die Betrachtung der Einflußgrößen ergab, daß die Aufgabe und die Verwendung des Datums im Prozeß für die Ermittlung der Anforderungen exakt bestimmt werden müssen. Aus diesem Grund war der Prozeß primär- und sekundärseitig in Abhängigkeit der Aufgabenstellung ausführlich zu beschreiben. Die Einflüsse der Aufbauorganisation waren ebenso wie die der Ablauforganisation zu berücksichtigen, darunter fielen auch die Auswirkungen der Automatisierungsansätze, z.B. durch den Einsatz flexibler Fertigungssysteme im Primärprozeß. Der Ansatz, von dem hier ausgegangen wurde, baut sich deshalb im ersten Schritt der vorgeschlagenen Vorgehensweise auf dem Modell eines Produktionssystems auf, das aus den Erkenntnissen von in mehreren Firmen durchgeführten Prozeßanalysen entwickelt wurde. In diesem Modell ist der Datenfluß und organisatorische Ablauf im Fertigungsprozeß in Matrixform festgehalten. Für jedes einzelne Prozeßdatum sind in der Matrix, bezogen auf die Aufgabenstellung, detailliert die Verwendungs- und Verflechtungsbeziehungen aufgezeichnet. Im zweiten Schritt erfolgt auf der Grundlage dieses Modells eine bedarfsgerechte Prozeßdatenauswahl. Die zeitliche Struktur des Datenflusses im Prozeß wird in Schritt drei mit Hilfe eines Ereignis-Zeitgraphens dargestellt. Die eigentliche zeitliche, quantitative und qualitative Anforderungsermittlung findet im vierten und gleichzeitig letzten Schritt anhand einer dafür entworfenen Datenanforderungsliste statt. Die Ergebnisse dieser anforderungsgerechten Datenanalyse nach der hier entwikkelten Systematik können in vielerlei Hinsicht Verwendung finden. Im Hinblick auf die eingangs genannten Problemstellungen sind beispielsweise folgende Einsatzmöglichkeiten denkbar und an Beispielen im einzelnen erläutert. - Verbesserung der Datenqualität - Rückkopplung im Sinne des kybernetischen Regelkreismodells - Bilden von Prozeßkenngrößen - Transparenz der EDV-Prozeßabläufe
Die Umsetzung der an sich seit längerem bekannten Logistikkonzepte stößt in vielen Unternehmen auf Schwierigkeiten. Oft fehlen durchgängige, prozessorientierte Gesamtlösungen. Zum Teil liegt dies daran, dass die üblichen PPS-Systeme im Feinplanungs- und Steuerungsbereich die gestiegenen logistischen Anforderungen nicht erfüllen können.
Logistische Funktionsketten mit der Integration von Information, Arbeits- und Materialflüssen für einen durchgängigen Auftragsabwicklungsprozeß müssen auch Qualitätssicherungsfunktionen mit beinhalten. Dies ist nur über eine entsprechende QS-Systemarchitektur zu realisieren, die an jeder Stelle im dispositiven und operativen Ablauf im Sinne der Fehlervermeidung dafür sorgt, daß die angestrebten Qualitätsziele erreicht werden.
The antimicrobial activity of a phagemixture and a lactic acid bacteriumagainst Staphylococcus aureus isolates from bovine origin was investigated in vitro with regard to possible applications in the therapy of udder inflammation (mastitis) caused by bacterial infections. The S. aureus isolates used for inoculation derived from quarter foremilk samples of mastitis cases. For the examination of the antimicrobial activity, the reduction of the S. aureus germ density was determined [log10 cfu/mL]. The phage mixture consisted of the three obligatory lytic and S. aureus-specific phages STA1.ST29, EB1.ST11 and EB1.ST27 (1:1:1). The selected Lactobacillus plantarum strain with proven antimicrobial properties and the phage mixture were tested against S. aureus in milk, both alone and in combination. The application of the lactic acid bacterium showed only a low reduction ability for a 24 h incubation period. The bacteriophage mixture as well as its combination with the lactic acid bacterium showed high antimicrobial activity against S. aureus for a 24 h incubation period at 37 C, with only the phage mixture showing significance.
Das Forschungscluster Industrie 4.0 stellt in acht Beiträgen aktuelle Ergebnisse aus seinen vielfältigen Forschungsprojekten vor. Es werden virtuelle Techniken in der Produktentwicklung, Lehrkonzepte für Industrie 4.0, Energy Harvesting bei Antennen, Energiemanagement in Produktionsanlagen, firmenübergreifende IT-Security Anforderungen, dezentral gesteuerte Produktionsprozesse und Spracherkennung mit Mikrocontrollern behandelt.
We present a feedback-corrected optimal scheduling approach to reduce the demand of electrical energy of batch processes, exemplified at the sand preparation in foundry. The main energy driver in the exemplary foundry is the idle time of the batch-wise working sand mixers. In this novel approach, we use linear integer programming to minimize the demand of energy of the sand mixers by scheduling the batches in real-time. For the optimization we use a physical model of the sand preparation, which takes dwell-times of the processes as dead-time systems into account. In this paper, we present the steps to make the optimal scheduling approach applicable for the production process. The application at the real production plant proves the performance of the suggested approach. Compared to the conventional control, the feedback-corrected optimal scheduling approach leads to an reduction in energy consumption of approximately 6.5 % without modifying the process or the aggregates.
The objective of this study was to investigate the occurrence of bacteremia in dairy cows with severe mastitis. Milk samples were collected from affected udder quarters, and corresponding blood samples were collected from dairy cows with severe mastitis at the time of diagnosis before any therapeutic measures were undertaken. The cultural detection of pathogens in blood classified a bacteremia. Further diagnostic tests were performed to provide evidence of bacteremia. This was realized by PCR with regard to S. aureus, E. coli and S. uberis and the Limulus test. Detection of culturable pathogens in the blood of cows with severe clinical mastitis was rare and occurred in only one of 70 (1.4%) cases. Overall, bacterial growth was detected in 53 of 70 (75.7%) milk samples. S. uberis (22/70), E. coli (12/70) and S. aureus (4/70) were the most frequently isolated pathogens from milk of cows with severe mastitis. PCR was performed in 38 of 70 (54.3%) blood samples. PCR was positive in eight of 38 cases. S. uberis was found most frequently in six blood samples (8.6%). E. coli was found on PCR in one blood sample (1.4%). S. aureus was identified in one blood sample (1.4%). When Coliforms were detected in the quarter milk sample, a Limulus test was performed in the corresponding blood sample. In three of 15 cases, the Limulus test was positive (4.3% of samples). Further studies are needed to investigate the occurrence of bacteremia in cows with severe mastitis in a higher population size.
The objective of this study was to investigate the association between teat skin colonization and intramammary infection (IMI) with Staphylococcus aureus or Streptococcus agalactiae at the quarter level in herds with automatic milking systems. Milk and teat skin samples from 1,142 quarters were collected from 300 cows with somatic cell count >200,000 cells/mL from 8 herds positive for Strep. agalactiae. All milk and teat skin samples were cultured on calf blood agar and selective media. A subset of samples from 287 quarters was further analyzed using a PCR assay (Mastit4 PCR; DNA Diagnostic A/S, Risskov, Denmark). Bacterial culture detected Staph. aureus in 93 (8.1%) of the milk samples and 75 (6.6%) of the teat skin samples. Of these, 15 (1.3%) quarters were positive in both the teat skin and milk samples. Streptococcus agalactiae was cultured in 84 (7.4%) of the milk samples and 4 (0.35%) of the teat skin samples. Of these, 3 (0.26%) quarters were positive in both the teat skin and milk samples. The PCR detected Staph. aureus in 29 (10%) of the milk samples and 45 (16%) of the teat skin samples. Of these, 2 (0.7%) quarters were positive in both the teat skin and milk samples. Streptococcus agalactiae was detected in 40 (14%) of the milk samples and 51 (18%) of the teat skin samples. Of these, 16 (5.6%) quarters were positive in both the teat skin and milk samples. Logistic regression was used to investigate the association between teat skin colonization and IMI at the quarter level. Based on bacterial culture results, teat skin colonization with Staph. aureus resulted in 7.8 (95% confidence interval: 2.9; 20.6) times higher odds of Staph. aureus IMI, whereas herd was observed as a major confounder. However, results from the PCR analyses did not support this association. Streptococcus agalactiae was isolated from the teat skin with both PCR and bacterial culture, but the number of positive teat skin samples detected by culture was too low to proceed with further analysis. Based on the PCR results, Strep. agalactiae on teat skin resulted in 3.8 (1.4; 10.1) times higher odds of Strep. agalactiae IMI. Our results suggest that Staph. aureus and Strep. agalactiae on teat skin may be a risk factor for IMI with the same pathogens. Focus on proper teat skin hygiene is therefore recommended also in AMS.
In der vorliegenden Arbeit wurde für die Erhebung von rheologischen Parametern ein großmaßstäbliches Rohrviskosimeter verwendet. Originalproben aus fünf Biogasfermentern und Nachgärern wurden mit variiertem Volumenstrom durch verschieden dimensionierte Messrohrstrecken im Kreis gefördert. Über definierte Längen der Messrohrstrecken konnte der Differenzdruck bei laminarem Strömungsverhalten aufgenommen werden. Aus den geometrischen Größen sowie den Wertepaaren Volumenstrom und Differenzdruck ließen sich nach einer Korrektur der Schergeschwindigkeit die Parameter für die Abbildung der absoluten Fließ- und Viskositätseigenschaften nach dem Potenzansatz approximieren.
Obwohl durchgängige CIM- und Logistik-Konzepte zur Erfüllung der permanent steigenden Kundenforderungen hinsichtlich spezifischer Produktausführungen bei qualitätsgerechter und termintreuer Auslieferung in den meisten Unternehmen noch nicht realisiert sind, beginnt bereits die Diskussion um eine neue Unternehmensstrategie: die "Lean Production". Das Ziel heißt diesmal, in allen Bereichen Ressourcen zu minimieren, um mit Hilfe einer schlanken Fertigung bei den Kosten Weltstandard zu erreichen.
The aim of this cross-sectional study was to investigate the occurrence of bacteremia in severe mastitis cases of dairy cows. Milk and corresponding blood samples of 77 cases of severe mastitis were bacteriologically examined. All samples (milk and blood) were incubated aerobically and anaerobically to also investigate the role of obligate anaerobic microorganisms in addition to aerobic microorganisms in severe mastitis. Bacteremia occurred if identical bacterial strains were isolated from milk and blood samples of the same case. In addition, pathogen shedding was examined, and the data of animals and weather were collected to determine associated factors for the occurrence of bacteremia in severe mastitis. If Gram-negative bacteria were detected in milk samples, a Limulus test (detection of endotoxins) was also performed for corresponding blood samples without the growth of Gram-negative bacteria. In 74 cases (96.1%), microbial growth was detected in aerobically incubated milk samples. The most-frequently isolated bacteria in milk samples were Escherichia (E.) coli (48.9%), Streptococcus (S.) spp. (18.1%), and Klebsiella (K.) spp. (16%). Obligatory anaerobic microorganisms were not isolated. In 72 cases (93.5%) of the aerobically examined blood samples, microbial growth was detected. The most-frequently isolated pathogens in blood samples were non-aureus Staphylococci (NaS) (40.6%) and Bacillus spp. (12.3%). The Limulus test was positive for 60.5% of cases, which means a detection of endotoxins in most blood samples without the growth of Gram-negative bacteria. Bacteremia was confirmed in 12 cases (15.5%) for K. pneumoniae (5/12), E. coli (4/12), S. dysgalactiae (2/12), and S. uberis (1/12). The mortality rate (deceased or culled) was 66.6% for cases with bacteremia and 34.1% for cases without bacteremia. High pathogen shedding and high humidity were associated with the occurrence of bacteremia in severe mastitis.
In order to reduce antimicrobial treatment and prevent environmental mastitis, the aim of the present study was to investigate associations between herd level factors and microbial load on teat ends with environmental mastitis pathogens. Quarterly farm visits of 31 dairy farms over a one-year period were used for statistical analysis. During each farm visit, teat-skin swabs, bedding and air samples were taken and management practices and herd parameters were documented. Total mesophilic bacteria, esculin-positive streptococci and coliform bacteria were examined in the laboratory procedures from teat skin and environmental samples. Esculin-positive streptococci and coliform bacteria on teat ends increased with high temperature–humidity indices (THI) in the barn during the spring and summer. Significantly more coliform bacteria on teat ends were found in herds with an increased percentage of normal or slightly rough teat ends. Cleaning cubicles more frequently, pre-cleaning teats before milking as well as post-dipping them after milking had a decreasing effect of teat-skin load with total mesophilic and coliform bacteria at the herd level. To conclude, teat-skin bacterial load with environmental pathogens is subject to fluctuations and can be influenced by aspects of farm hygiene.
Die Anpassungsfähigkeit eines Unternehmens an rasch wechselnde Wettbewerbssituationen bei kundenwunschorientierter Produktion mit veränderlichen Losgrößen und unterschiedlichen Terminrestriktoren kann nur über ausgefeilte Strategien und durch DV-Einsatz erzeugt werden. Anforderungsgerechte CIM- und Logistik-Konzepte sind eine wesentliche Vorraussetzung, damit die geforderte Flexibilität erreicht wird. Den unabdingbaren Informationsfluss schafft hierbei die Betriebsdatenerfassung.
Wegen der Vielzahl unterschiedlicher Teile in variierenden Losgrößen ist es in der spanenden Fetigung besonders wichtig, Hardware und Software für logistische Aufgaben anforderungsgerecht auszuwählen. Ausgehend von den logistischen Grundfunktionen im Betrieb sind die Grunddatenbereitstellung, die Prozessstruktur, die Produktgestaltung, das Beschaffen und das Lagern auf die rechnergestützte Logistik auszurichten.
Für die Produktion von drei Sorten stichfestem Joghurt (Natur, mit unterlegter Frucht und Mix) werden die Kosten nach einer speziellen Form der Teilkostenrechnung in Abhängigkeit von der Kapazitätsauslastung bestimmt. Es werden drei Modelle mit unterschiedlicher Kapazitätsgröße dargestellt: 6500, 13.000 und 26.000 Becher/h. Durch Variationen der Produktmenge, Produktionstage und Produktanteile ergeben sich Kosten zwischen 12,6 und 9,3 Pf/Becher Joghurt Natur bzw. 18,7 und 15,5 Pf/Becher Joghurt mit unterlegter Frucht bzw. 17,0 und 14,0 Pf/Becher Joghurt Mix. Je nach Produktionsbedingungen können Stückkostendifferenzen von über 20 Pfennig je kg Produkt auftreten.
In dieser Arbeit werden die Grundlagen zur Bestimmung des Kostenverlaufs einzelner ausgewählter Molkereibetriebsabteilungen bei unterschiedlichen Kapazitätsgrößen und -auslastungen bestimmt. Den Produkten (Abteilungen) werden die mengenproportionalen Produkteinzelkosten zugerechnet sowie die Gemeinkosten der Abteilung, die sich aus jahresfixen, tagesfixen und chargenfixen Kosten zusammensetzen. Für Energie werden lediglich mengenproportionale Kosten in Ansatz gebracht. Die sonstigen Kosten der Hilfskostenstellen werden grundsätzlich nicht auf die Produkte bzw. Abteilungen umgelegt; sie werden im letzten Teil dieser Veröffentlichungsreihe behandelt. Die objektive Vergleichbarkeit der Kosten kann so gewährleistet werden. Ein wichtiger Bestandteil dieser Arbeit war die Entwicklung eines für alle Abteilungen brauchbaren Simulationsmodells, das für den Einsatz in der EDV konzipiert wurde. Neben der Berechnung der anfallenden Kosten bei unterschiedlichen Anlagengrößen sind bei dem Computermodell beliebige Variationen der folgenden Faktoren möglich. Dadurch können die Auswirkungen eines veränderten Beschäftigungsgrades bzw. einer anderen Kapazitätsauslastung auf die Stückkosten der einzelnen Produkte ermittelt werden. Es ist vorgesehen, die Daten über Jahre hinaus auf dem neuesten Stand zu halten und zu veröffentlichen.
In der vorliegenden Arbeit werden die Kosten der Sprühtrocknung bei drei verschiedenen Kapazitätsgrößen mit jeweils variierender Kapazitätsauslastung nach einer speziellen Form der Teilkostenrechnung bestimmt. Die Kapazitätsgrößen betragen 10800, 21600 und 32400 kg Magermilch pro Stunde. Die verarbeiteten Milchmengen liegen
zwischen 12,8 Mio. und 256,6 Mio. kg im Jahr; dabei variieen die Stückkosten zwischen 4,80 und 1,78 Pf/kg Mm. Es hat sich dabei gezeigt, daß die Kostendegression bedeutend stärker durch den Grad der Kapazitätsauslastung als durch die Kapazitätsgröße beeinflußt wird.
In der vorliegenden Arbeit werden die Kosten für die Produktion von Speisequark mager und Speisequark 40 % F.i.Tr. für zwei Kapazitätsgrößen von 4.800 bzw. 9.500 kg Km/h nach einer speziellen Form der Teilkostenrechnung bestimmt. Bei Variationen der Kapazitätsauslastung (Pro
duktionstage X Produktionsstunden/Tag) und der Produktanteile ergeben sich Kosten zwischen 11,99 und 18,95 Pf pro Becher Speisequark mager bzw. 11,73 und 18,45 Pf je Becher Speisequark 40% F.i.Tr. Das entspricht einer Differenz in den Stückkosten von durchschnittlich 27,5 Pf/kg Speisequark. Es zeigt sich dabei, daß die Kostendegression bedeutend stärker durch den Grad der Kapazitätsauslastung als durch die Kapazitätsgröße beeinflußt wird.
Mastitis poses a considerable threat to productivity and to animal welfare on modern dairy farms. However, the common way of antibiotic treatment does not always lead to a cure. Unsuccessful cures can, among other reasons, occur due to biofilm formation of the causative agent. This has attracted interest from researchers to introduce promising alternative therapeutic approaches, such as the use of beneficial lactic acid bacteria (LAB). In fact, using LAB for treating mastitis probably requires the formation of a beneficial biofilm by the probiotic bacteria. The present study investigated the ability of five LAB strains, selected on the basis of results from previous studies, to remove and to replace pathogenic biofilms in vitro. For this purpose, Staphylococcus (S.) aureus ATCC 12,600 and two strains—S. xylosus (35/07) and S. epidermidis (575/08)—belonging to the group of coagulase negative staphylococci (CNS) were allowed to form biofilms in a 96-well plate. Subsequently, the LAB were added to the well. The biofilm challenge was evaluated by scraping off and suspending the biofilm cells, followed by a plate count of serial dilutions using selective media. All the LAB strains successfully removed the staphylococcal biofilms. However, only Lactobacillus (L.) rhamnosus ATCC 7469 and L. plantarum 2/37 formed biofilms of their own to replace the pathogenic ones.
Mastitis is one of the most important diseases threatening modern dairy herds. The idea of fighting the disease through colonising the udder with lactic acid bacteria (LAB), thereby building a beneficial biofilm, is the base for a probiotic approach towards mastitis control. The purpose of this study was to screen 13 LAB strains (eleven wild strains, two ATCC strains) inhibitory to the growth of mastitis-causing pathogens for their in vitro ability to form a biofilm and to adhere to bovine glandular mammary epithelium in order to assess their probiotic potential. Furthermore, we aimed to gain knowledge about the chemical nature of the adhesins involved by subjecting the bacteria to various chemical and enzymatical pre-treatments. The biofilms were grown on hydrophilic glass and on hydrophobic polypropylene in de Man, Rogosa and Sharpe (MRS) broth and afterwards quantified with a crystal violet assay. Biofilm formation was observed in all strains. However, the extent strongly depended on the strain, surface charge and medium. The adhesion assay also revealed a strong strain dependency, but this trait was also present in all of the investigated LAB isolates. Depending on the strain, chemical or enzymatical pre-treatment revealed carbohydrate molecules as well as proteins and lipids to be crucial for the adhesion of LAB to epithelial cells. The seven strains showing the strongest biofilm formation and/or adhesion represent promising candidates for further investigation in order to develop a probiotic remedy for the treatment of mastitis. Still, their safety for consumers and patients as well as their capability to colonise the udder remain to be investigated in in vivo studies.
One of the main concerns of this publication is to furnish a more rational basis for discussing bioplastics and use fact-based arguments in the public discourse. Furthermore, “Biopolymers – facts and statistics” aims to provide specific, qualified answers easily and quickly for decision-makers in particular from public administration and the industrial sector. Therefore, this publication is made up like a set of rules and standards and largely foregoes textual detail. It offers extensive market-relevant and technical facts presented in graphs and charts, which means that the information is much easier to grasp. The reader can expect comparative market figures for various materials, regions, applications, process routes, agricultural land use, water use or resource consumption, production capacities, geographic distribution, etc.
The IfBB – Institute for Bioplastics and Biocomposites is a research institute within the Hochschule Hannover, University of Applied Sciences and Arts, which was established in 2011 to respond to the growing need for expert knowledge in the area of bioplastics. With its practice-oriented research and its collaboration with industrial partners, the IfBB is able to shore up the market for bioplastics and, in addition, foster unbiased public awareness and understanding of the topic. As an independent research-led expert institution for bioplastics, the IfBB is willing to share its expertise, research findings and data with any interested party via the Internet, online and offline publications or at fairs and conferences. In carrying on these efforts, substantial information regarding market trends, processes and resource needs for bioplastics is being presented here in a concise format, in addition to the more detailed and comprehensive publication and “Engineering Biopolymers”1.
One of our main concerns is to furnish a more rational basis for discussing bioplastics and use fact-based arguments in the public discourse. Furthermore, “Biopolymers – facts and statistics” aims to provide specific, qualified answers easily and quickly for decision-makers in particular from public administration and the industrial sector. Therefore, this publication is made up like a set of rules and standards and largely foregoes textual detail. It offers extensive market-relevant and technical facts presented in graphs and charts, which means that the information is much easier to grasp. The reader can expect comparative market figures for various materials, regions, applications, process routes, agricultural land use or resource consumption, production capacities, geographic distribution, etc.
One of the main concerns of this publication is to furnish a more rational basis for discussing bioplastics and use fact-based arguments in the public discourse. Furthermore, “Biopolymers – facts and statistics” aims to provide specific, qualified answers easily and quickly for decision-makers in particular from public administration and the industrial sector. Therefore, this publication is made up like a set of rules and standards and largely foregoes textual detail. It offers extensive market-relevant and technical facts presented in graphs and charts, which means that the information is much easier to grasp. The reader can expect comparative market figures for various materials, regions, applications, process routes, agricultural land use, water use or resource consumption, production capacities, geographic distribution, etc.
One of the main concerns of this publication is to furnish a more rational basis for discussing bioplastics and use fact-based arguments in the public discourse. Furthermore, “Biopolymers – facts and statistics” aims to provide specific, qualified answers easily and quickly for decision-makers in particular from public administration and the industrial sector. Therefore, this publication is made up like a set of rules and standards and largely foregoes textual detail. It offers extensive market-relevant and technical facts presented in graphs and charts, which means that the information is much easier to grasp. The reader can expect comparative market figures for various materials, regions, applications, process routes, agricultural land use, water use or resource consumption, production capacities, geographic distribution, etc.
One of the main concerns of this publication is to furnish a more rational basis for discussing bioplastics and use fact-based arguments in the public discourse. Furthermore, “Biopolymers – facts and statistics” aims to provide specific, qualified answers easily and quickly for decision-makers in particular from public administration and the industrial sector. Therefore, this publication is made up like a set of rules and standards and largely foregoes textual detail. It offers extensive market-relevant and technical facts presented in graphs and charts, which means that the information is much easier to grasp. The reader can expect comparative market figures for various materials, regions, applications, process routes, agricultural land use, water use or resource consumption, production capacities, geographic distribution, etc.
One of the main concerns of this publication is to furnish a more rational basis for discussing bioplastics and use fact-based arguments in the public discourse. Furthermore, “Biopolymers – facts and statistics” aims to provide specific, qualified answers easily and quickly for decision-makers in particular from public administration and the industrial sector. Therefore, this publication is made up like a set of rules and standards and largely foregoes textual detail. It offers extensive market-relevant and technical facts presented in graphs and charts, which means that the information is much easier to grasp. The reader can expect comparative market figures for various materials, regions, applications, process routes, agricultural land use, water use or resource consumption, production capacities, geographic distribution, etc.
One of the main concerns of this publication is to furnish a more rational basis for discussing bioplastics and use fact-based arguments in the public discourse. Furthermore, “Biopolymers – facts and statistics” aims to provide specific, qualified answers easily and quickly for decision-makers in particular from public administration and the industrial sector. Therefore, this publication is made up like a set of rules and standards and largely foregoes textual detail. It offers extensive market-relevant and technical facts presented in graphs and charts, which means that the information is much easier to grasp. The reader can expect comparative market figures for various materials, regions, applications, process routes, agricultural land use, water use or resource consumption, production capacities, geographic distribution, etc.
One of the main concerns of this publication is to furnish a more rational basis for discussing bioplastics and use fact-based arguments in the public discourse. Furthermore, “Biopolymers – facts and statistics” aims to provide specific, qualified answers easily and quickly for decision-makers in particular from public administration and the industrial sector. Therefore, this publication is made up like a set of rules and standards and largely foregoes textual detail. It offers extensive market-relevant and technical facts presented in graphs and charts, which means that the information is much easier to grasp. The reader can expect comparative market figures for various materials, regions, applications, process routes, agricultural land use, water use or resource consumption, production capacities, geographic distribution, etc.
One of the main concerns of this publication is to furnish a more rational basis for discussing bioplastics and use fact-based arguments in the public discourse. Furthermore, “Biopolymers – facts and statistics” aims to provide specific, qualified answers easily and quickly for decision-makers in particular from public administration and the industrial sector. Therefore, this publication is made up like a set of rules and standards and largely foregoes textual detail. It offers extensive market-relevant and technical facts presented in graphs and charts, which means that the information is much easier to grasp. The reader can expect comparative market figures for various materials, regions, applications, process routes, agricultural land use, water use or resource consumption, production capacities, geographic distribution, etc.
Streptococcus (S.) uberis is a causative agent for clinical and subclinical bovine mastitis which significance for the udder health has increased over the last decades. Molecular diagnosis methods revealed that S. uberis may be subdivided into many different varieties with different epidemiological properties. In addition, some varieties were reclassified as Streptococcus parauberis and Globicatella sanguinis. The present paper reviews S. uberis and its role in modern dairy farming. This pathogen is ubiquitous for which it is considered as environment- associated. Straw bedding and pasture, but also the bovine skin and digestive mucosae are typical localizations inhabited by S. uberis. Due to its capacity to persist within the mammary tissue, some infections may eventually turn cow-associated. In other cases, the infection is short, but in any case, there is a high risk of re-infection. Although many varieties remain susceptible to most antimicrobial agents, the problem for the dairy farm lies in the high rate of re-infection. This paper also reviews risk factors, therapies and measures to control S. uberis at farm level.
Das Versagen von Klebungen kann durch ungenügende Adhäsion, Alterungsprozesse oder mechanische Spannungen erfolgen. In der SMD-Technologie werden Werkstoffe geklebt, die verschiedene Ausdehnungskoeffizienten besitzen. Bei SMD-Klebverbindungen gewährleistet die nachfolgende Lötung deren Langzeitfestigkeit. Wurde für eine gute Adhäsion reichlich Vorsorge getroffen und die Klebung versagt trotzdem, stellt sich die Frage: Spielen mechanische Eigenschaften für den Einsatz von SMD-Klebstoffen eine Rolle?
To optimise udder health at the herd level, identifying incurable mastitis cases as well as providing an adequate therapy and culling strategy are necessary. Cows with clinical mastitis should be administered antibiotic medication if it is most likely to improve mammary cure. The somatic cell count (SCC) in milk of the monthly implemented Dairy Herd Improvement (DHI) test represents the most important tool to decide whether a cow has a promising mammary cure rate. Differential cell count (DCC) facilitates the specification of the immunological ability of defence, for example by characterising leukocyte subpopulations or cell viability. The aim of this study was to assess the DCC and cell viability in DHI milk samples regarding the cytological (CC) and bacteriological cure (BC) of the udder within a longitudinal study, thereby gaining a predictive evaluation of whether a clinical mastitis benefits from an antibiotic treatment or not. The cows enrolled in this study had an SCC above 200,000 cells/mL in the previous DHI test. Study 1 assessed the CC by reference to the SCC of two consecutive DHI tests and included 1010 milk samples: 28.4% of the mammary glands were classified as cytologically cured and 71.6% as uncured. The final mixed logistic regression model identified the total number of non-vital cells as a significant factor associated with CC. An increasing amount of non-vital cells was related to a lower individual ability for CC. Cows which were in the first or second lactation possessed a higher probability of CC than cows having a lactation number above two. If animals developed a clinical mastitis after flow cytometric investigation, the BC was examined in study 2 by analysing quarter foremilk samples microbiologically. Taking 48 milk samples, 81.3% of the mammary glands were classified as bacteriologically cured and 18.7% as uncured. The percentage of total non-vital cells tended to be lower for cows which were cured, but no significance could be observed. This study revealed that the investigation of the proportion of non-vital cells in DHI milk samples can enhance the prognosis of whether an antibiotic treatment of clinical mastitis might be promising or not. Prospectively, this tool may be integrated in the DHI tests to facilitate the decision between therapy or culling.
We report the unambiguous detection of phenyl groups covalently attached to functionalised graphene using non-linear spectroscopy. Sum-frequency generation was employed to probe graphene on a gold surface after chemical functionalisation using a benzene diazonium salt. We observe a distinct resonance at 3064 cm1 which can clearly be assigned to an aromatic C–H stretch by comparison with a self-assembled monolayer on a gold substrate formed from benzenethiol. Not only does sum-frequency generation spectroscopy allow one to characterise functionalised graphene with higher sensitivity and much better specificity than many other spectroscopic techniques, but it also opens up the possibility to assess the coverage of graphene with functional groups, and to determine their orientation relative to the graphene surface.
The control of clinical mastitis on dairy farms is an essential part of animal health management. Knowledge of the causative microorganisms, the cure rates achievable in the field and essential associated factors are crucial for proper control. The objectives of the present study were to characterize clinical mastitis cases in Germany and to analyze factors influencing cure rates and the recurrence rate. Milk samples of every clinical mastitis case occurring on 12 participating farms were examined cytomicrobiologically. Post-treatment quarter samples were taken after 14 and 21 days. Treatments were performed according to existing farm protocols. Of 2883 clinical mastitis cases, the most prevalent pathogens were Streptococcus (S.) uberis (20.2%) and coliforms (11.6%). In 35% of the milk samples, no bacteriological growth was detected. The overall bacteriological cure rate was 73.3%, while the cytological cure rate was 22.3%, the full cure rate 21.4% and the recurrence rate 18.8%. Regarding the pathogen distribution of severe mastitis, coliform bacteria were detected in 30.5% of the cases, whereas S. uberis was detected in 26.5% thereof. The results show that severe mastitis is caused almost as frequently by Gram-positive as by Gram-negative microorganisms. The low cytological cure rates show that the therapy needs to be further developed with regard to calming the inflammation. The obtained data can be very helpful in assessing internal mastitis scenarios and the effect of measures and therapies.
Eine ganzheitliche CIM-Einführung setzt neben einer Veränderung der Organisation vor allem ein integratives Informationsmanagement voraus. Die Notwendigkeit zu gesamtheitlichem Denken in funktionsübergreifenden Zusammenhängen erfordert in erster Linie Führungsqualität und Mitarbeiterqualifikation. Diesem Umstand wird in dem vom Autor vorgestellten CIM-house-Modell ausdrücklich Rechnung getragen.
Aus den Veröffentlichungen über CIM-Projekte geht immer häufiger hervor, dass der von den Anbietern vertretene hohe Anspruch einer umfassenden CIM-Anwendung und die Ergebnisse durchgeführter CIM-Realisierungen in der Praxis nicht übereinstimmen. Es wäre jedoch falsch, aufgrund dieser Beobachtungen die CIM-Strategie als solche in Frage zu stellen. Der Ausweg aus diesem Missstand ist vielmehr über geeignete CIM-Einführungsstrategien zu suchen.
Die folgende Studie befasst sich mit den Auswirkungen der Corona-Pandemie und deren Effekt – ein verminderter CO2-Ausstoß in Deutschland. Für einen übersichtlichen Vergleich wird im weiteren Verlauf in unterschiedlichen Szenarien darauf eingegangen, wie sich der CO2-Ausstoß im Vergleich zu 2020 ohne die Corona-Pandemie in Deutschland verändern könnte. Grundbasis für die Ermittlungen der folgenden Szenarien ist der CO2-Trend ohne die Corona-Pandemie im Jahr 2020, in dem Deutschland das Emissionsziel von -40 % gegenüber 1990 mit einer Reduktion von lediglich 37 % verfehlt hätte. Im zweiten Szenario wird dargestellt, wie sich die aktuelle Corona-Pandemie mit verschiedenen Lockdown-Phasen auf den CO2-Ausstoß auswirkt. Deutlich wird hierbei, dass trotz der aktuellen Maßnahmen eine längere Lockdown-Phase benötigt wird, um das Klimaziel von -40 % langfristig gesichert zu erreichen. In den Szenarien 3 und 4 liegt der Fokus auf möglichen Handlungs- und Verhaltensweisen nach der Pandemie. Das Szenario 3 betrachtet die Folgen von wirtschaftsfördernden Maßnahmen nach dem Lockdown und dem damit einhergehenden CO2-Anstieg. Wie viel CO2 zusätzlich aufgrund von nachhaltigem und klimaorientiertem Verhalten eingespart werden kann, erläutert das Szenario 4 „CO2 Entwicklung unter Berücksichtigung der Corona-Pandemie 2020 und möglicher positiver Umweltentwicklungen aus dem Lockdown“.
Faktoren, wie die wachsende Bevölkerung, sich verändernde Produktionsfaktoren oder Umwelteinflüsse wurden vernachlässigt. Die Studie zeigt, dass die Chancen, die durch die wirtschaftlichen Einschnitte und die Verhaltensänderungen, die durch die Corona-Pandemie bzw. deren Folgen hervorgerufen wurden, einen maßgeblichen Einfluss auf den CO2-Ausstoß der Bundesrepublik Deutschland haben können.
Continuous Fiber-Reinforced Material Extrusion with Hybrid Composites of Carbon and Aramid Fibers
(2022)
An existing challenge in the use of continuous fiber reinforcements in additively manufactured parts is the limited availability of suitable fiber materials. This leads to a reduced adaptability of the mechanical properties to the load case. The increased design freedom of additive manufacturing allows the flexible deposition of fiber strands at defined positions, so that even different fiber materials can be easily combined in a printed part. In this work, therefore, an approach is taken to combine carbon and aramid fibers in printed composite parts to investigate their effects on mechanical properties. For this purpose, tensile, flexural and impact tests were performed on printed composite parts made of carbon and aramid fibers in a nylon matrix with five different mixing ratios. The tests showed that the use of hybrid composites for additive manufacturing is a reasonable approach to adapt the mechanical properties to the loading case at hand. The experiments showed that increasing the aramid fiber content resulted in an increase in impact strength, but a decrease in tensile and flexural strength and a decrease in stiffness. Microstructural investigations of the fracture surfaces showed that debonding and delamination were the main failure mechanisms. Finally, Rule of Hybrid Mixture equations were applied to predict the mechanical properties at different mixture ratios. This resulted in predicted values that differed from the experimentally determined values by an average of 5.6%.
The speed control system for a concept for cost effective drives with high precision is presented. The drive concept consists of two parallel working drives. The concept is an alternative to direct drives. One big advantage is the use of standard gear boxes with economical components. This paper deals with the control of the drive system consisting of two parts: one drive produces the power for the machine, another drive makes the motion precice and dynamic. Both drives are combined to one double drive by a control system. The drive system is usefull for printing machines and other machines with high power consumption at a nearly constant speed and high accuracy requirements. The calculation for a drive system with 37 kW shows, that the control drive has to supply only about 20 % of the total torque and power needed to compensate the errors of the power drive. The stability of the system is shown by a simulation of the double drive.