Die Wertstrommethode im Zeitalter von Industrie 4.0 - Studienreport

Im Zeitraum von Oktober bis Dezember 2016 wurde vom Lehrstuhl für Produktionswirtschaft der Brandenburgischen Technischen Universität Cottbus-Senftenberg die Studie mit dem Titel „Die Wertstrommethode im Zeitalter von Industrie 4.0“ als Online-Umfrage durchgeführt. 170 Personen beantworteten den Fragebogen vollständig, allesamt haben Erfahrungen mit Lean Production. Die zunehmende Volatilität der Märkte sowie die fortschreitende Digitalisierung werden als die größten Herausforderungen für Produktion/Produktionssystem gesehen. Als größter Nachteil der Wertstrommethode gilt, dass sie nur ein statisches Tool ist bzw. eine Momentaufnahme darstellt. Am meisten werden an der Wertstrommethode die Transparenz hinsichtlich Engpässen und Problemen sowie die Möglichkeit zur Ableitung von Verbesserungsthemen geschätzt. Knapp die Hälfte der Befragten aktualisiert Dokumente von Wertstromanalyse und -design höchstens einmal pro Jahr. Der Aufwand dafür ist höchst unterschiedlich und reicht von einem bis zu mehr als 20 Manntagen. Kurz- und mittelfristig wird eine autonome Produktionssteuerung in der Serien- und Massenfertigung nicht als realistisch angesehen. Die Bedeutung der Wertstrommethode wird damit weiterhin groß bleiben. Die große Mehrheit der Teilnehmer sieht überwiegend keine Widersprüche zwischen Industrie 4.0 und der Lean-Philosophie, hält Lean nach wie vor für wichtig und plädiert für eine Integration von Lean und Industrie 4.0. Als besonders groß wird bei der Integration von Lean und Industrie 4.0 das Potential zur Steigerung der Flexibilität angesehen. Ein Großteil der Experten ist der Meinung, dass künftige Herausforderungen der Produktion auch Auswirkungen auf die klassische Wertstrommethode haben werden. Zwei Drittel der Befragten halten eine Weiterentwicklung der Methode mit Industrie 4.0-Lösungen deshalb für sinnvoll. Von besonderem Interesse sind für die Studienteilnehmer dabei die Möglichkeit der Simulation, die Echtzeit-Integration von Produktions- und Maschinendaten sowie die Schaffung einer Schnittstelle zu ERP-/MES-Systemen. Dabei sollen die Aspekte Transparenz der Prozesse, die Einbeziehung aller Beteiligten sowie die Möglichkeit zur Ableitung von Verbesserungsthemen unbedingt berücksichtigt werden

Proteome profiling by label‐free mass spectrometry reveals differentiated response of Campylobacter jejuni 81–176 to sublethal concentrations of bile acids.

Purpose Bile acids are crucial components of the intestinal antimicrobial defense and represent a significant stress factor for enteric pathogens. Adaptation processes of Campylobacter jejuni to this hostile environment are analyzed in this study by a proteomic approach. Experimental design Proteome profiling by label-free mass spectrometry (SWATH-MS) has been used to characterize the adaptation of C. jejuni to sublethal concentrations of seven bile acids. Results The bile acids with the lowest inhibitory concentration (IC50), deoxycholic and chenodeoxycholic acid, induce the most significant proteome changes. Overall a downregulation of all basic biosynthetic pathways and a general decrease in the transcription machinery are found. Concurrently, an induction of factors involved in detoxification of reactive oxygen species, protein folding, and bile acid exporting efflux pumps is detected. Exposure to deoxycholic and chenodeoxycholic acid results in an increased expression of components of the more energy-efficient aerobic respiration pathway, while the anaerobic branches of the electron transport chain are down-expressed. Conclusions and clinical relevance The results show that C. jejuni has a differentiated system of adaptation to bile acid stresses. The findings enhance the understanding of the pathogenesis of campylobacteriosis, especially for survival of C. jejuni in the human intestine, and may provide clues to future medical treatment

Einfluss der N-Form (Nitrat versus Ammonium) und des Wasserangebotes auf das Wachstum der Tomatenpflanze (Lycopersicon esculentum L.)

Es wurde der Einfluss der N-Form (NO3- versus NH4+) und des Begleitions zu Ammonium (Cl- versus SO42-) in Abhängigkeit vom Wasserangebot auf das Wachstum der Tomaten-pflanze und die Qualität der Frucht untersucht. Dabei erwies sich ein Mischangebot von Nitrat und Ammonium als das günstigste. Ein hoher Ammoniumanteil führt zu keinem Zeitpunkt zu Wachstumsdepressionen. Milder Wasser-stress dagegen zieht eine geringere Trockenmassenproduktion nach sich, wirkt sich aber, wie auch eine Ammoniumernährung, positiv auf die Fruchtqualität aus. Ein Vergleich der beiden Begleitionen Chlorid und Sulfat bestätigt die Funktion des Chlorids als alternatives Osmotikum zu Nitrat. Sulfat wird unabhängig von der Behandlung in den Blättern gespeichert und reduziert, Carboxylate und lösliche Kohlenhydrate als alternative Osmotika gebildet. Bei einem Ammoniumangebot wie auch bei mildem Wasserstress nehmen die Wasserauf-nahmerate und die Transpirationsrate ab. Die Wassernutzungseffizienz nimmt zu. Chlorid als Begleition erhöht die Transpirationsrate sowie die Ammoniumaufnahme

Application of Fluorous Polymer Matrixes in Ion-Selective Elcetrodes

University of Minnesota Ph.D. dissertation.August 2016. Major: Chemistry. Advisor: Philippe Buhlmann. 1 computer file (PDF); xviii, 207 pages.Polyperfluoro(4-vinyloxy-1-butene), which is also known as Cytop, and poly[4,5-difluoro-2,2,-bis (trifluoromethyl)-1,3-dioxole]-co-poly(tetrafluoroethylene) copolymers with dioxole monomer contents of 65% or 87% (known as Teflon AF1600 and Teflon AF2400, respectively) were plasticized with four fluorous compounds. While plasticization of all polymers with perfluoroperhydrophenanthrene, perfluoro(1-methyldecalin), a perfluorotetraether with three trifluoromethyl side groups and one hydrogen atom, and a linear perfluorooligoether with an average of 14.3 ether groups per molecule was successful, these four plasticizers affected the twelve blends very differently. A threshold of plasticization beyond which further increases in the plasticizer volume fraction did not further affect the glass transition temperature, Tg, was observed for some blends. Also, the limit of miscibility ranged from as low as 20% plasticizer content to complete miscibility at all volume fractions. The blends of Teflon AF2400 or Teflon AF1600 with high contents of the linear perfluorooligoether provided Tg values as low as –114 ºC, lower than for any other fully miscible blend. The occurrence of two glass transitions in an intermediate range of plasticizer volume ratios for these two types of blends can be explained by distinct local environments rather than macroscopic phase separation, as anticipated by the Lodge-McLeish model. In spite of the widespread use of perfluorinated solvents with amino and ether groups in a variety of application fields, the coordinative properties of these compounds are poorly known. It is generally assumed that the electron withdrawing perfluorinated moieties render these functional groups rather inert, but little is known quantitatively about the extent of their inertness. This chapter reports on the interactions between inorganic monocations and perfluorotripentylamine and 2H-perfluoro-5,8,11-trimethyl-3,6,9,12-tetraoxapentadecane, as determined with fluorous liquid-membrane cation-selective electrodes doped with tetrakis[3,5-bis(perfluorohexyl)phenyl]borate salts. The amine does not undergo measurable association with any ion tested, and its formal pKa is shown to be smaller than –0.5. This is consistent with the nearly planar structure of the amine at its nitrogen center, as obtained with density functional theory calculations. The 2HPFTE interacts very weakly with Na+ and Li+. Assuming 1:1 stoichiometry, formal association constants were determined to be 2.3 and 1.5 M-1, respectively. This disproves an earlier proposition that the Lewis base character in such compounds may be non-existent. Due to the extremely low polarity of fluorous solvents and the resulting high extent of ion pair formation, a fluorophilic electrolyte salt with perfluoroalkyl substituents on both the cation and the anion had to be developed for these experiments. In its pure form, this first fluorophilic electrolyte salt is an ionic liquid with a glass transition temperature, Tg, of -18.5 ºC. Interestingly, the molar conductivity of solutions of this salt increases very steeply in the high concentration range, making it a particularly effective electrolyte salt. Fluorous media are the least polar and polarizable condensed phases known. Their use as membrane materials considerably increases the selectivity and robustness of ion-selective electrodes (ISEs). In this research, a fluorous amorphous perfluoropolymer was used for the first time as a matrix for an ISE membrane. Electrodes for pH measurements with membranes composed of poly[4,5-difluoro-2,2,-bis(trifluoromethyl)-1,3-dioxole]-co-poly(tetrafluoroethylene) (known as Teflon AF) as polymer matrix, a linear perfluorooligoether as plasticizer, sodium tetrakis(3,5-bis(perfluorohexyl)phenyl)borate providing for ionic sites, and bis[(perfluorooctyl)propyl]-2,2,2-trifluoroethylamine as H+-ionophore were investigated. All electrodes had excellent potentiometric selectivities, showed Nernstian responses to H+ over a wide pH range, exhibited enhanced mechanical stability and maintained their selectivity over at least four weeks. For membranes of low ionophore concentration, the polymer affected the sensor selectivity noticeably at polymer concentrations exceeding 15%. Also, the membrane resistance increased quite strongly at high polymer concentrations, which cannot be explained by the Mackie-Meares obstruction model. The selectivities and resistances depend on the polymer concentration because of a functional group associated with Teflon AF2400, with a concentration of one functional group per 854 monomer units of the polymer. In the fluorous environment of these membranes, this functional group binds to Na+, K+, Ca2+, and the unprotonated ionophore with binding constants of 103.5, 101.8, 106.8 and 104.4 M–1, respectively. Potentiometric and spectroscopic evidence indicates that these functional groups are COOH groups formed by the hydrolysis of carboxylic acid fluoride C(꞊O)F groups originally present in Teflon AF2400. The use of higher ionophore concentrations removes the undesirable effect of these COOH groups almost completely. Alternatively, the C(꞊O)F groups can be eliminated chemically. In this work we demonstrate the remarkable stability of fluorous-based ion-selective electrode (ISE) membranes by exposing them to a cleaning-in-place treatment, CIP, as it is used in many industrial processes. The sensing membranes were made up of a linear perfluoropolyether as membrane matrix, 0.5 mmol/kg ionic sites (tetrakis[3,5-bis(perfluorohexyl)phenyl]borate), 2 mmol/kg ionophore (tris[(perfluorooctyl)propyl]amine or tris[(perfluorooctyl)pentyl]amine), and Teflon AF2400. To mimic a typical CIP treatment, the electrodes were repeatedly exposed for 30 min to 3.0% NaOH solution at 90 ºC (pH ≈12.7). After ten exposures and a total of 5 h at 90 ºC, the fluorous sensing membranes doped with the more selective ionophore still showed the ability to respond with a theoretical (Nernstian) slope without loss in selectivity. Addition of a fluorophilic electrolyte salt reduced the membrane resistance by an order of magnitude

Characterization of Human Endogenous Retrovirus Type K Virus-like Particles Generated from Recombinant Baculoviruses

AbstractThe family of human endogenous retrovirus type K (HERV-K) comprises members with long open reading frames (ORF) for retroviral proteins. The existence of a biologically active provirus with replicative capacities has not yet been demonstrated. To confirm the assumption that HERV-K codes for the previously observed retrovirus-like particles (human teratocarcinoma-derived virus, HTDV) in human teratocarcinoma cells, we have constructed recombinant full-length HERV-K cDNA-based baculoviruses withgag, pro, pol,andenvORFs. Two viral constructs were used for infections of insect cells, one bearing 67 bp of the 5′ untranslated region upstream of the 5′ splice donor (SD) site and of the retroviral genes, the second omitting the SD sequence. For both recombinant viruses, indirect immunofluorescence and laser scan analyses revealed expression of HERV-K Gag protein. Electron microscopy studies demonstrated efficient production of virus-like particles (VLPs) at the cytoplasmic cell membranes. These VLPs are morphologically identical with the HTDV phenotype. In immunoelectron microscopy of ultrathin frozen sections, anti-HERV-K Gag antibodies specifically reacted with HERV-K VLPs. In Western blots, in addition to the 76-kDa precursor protein, the putative major core protein with an apparent molecular mass of 32 kDa exhibited predominant immunoreactivity with anti-Gag antiserum. In contrast, neither HERV-K Env nor cORF proteins could be detected due to inefficient mRNA splicing. Purified particles from insect cell culture supernatants tested in an ultrasensitive reverse transcriptase assay revealed weak polymerase activity. The data demonstrate that HERV-K codes for retroviral particles of the HTDV phenotype

Theory for the reduction of products of spin operators

In this study we show that the sum of the powers of arbitrary products of quantum spin operators such as $(S^+)^l(S^-)^m(S^z)^n$ can be reduced by one unit, if this sum is equal to 2S+1, S being the spin quantum number. We emphasize that by a repeated application of this procedure \em all \em arbitrary spin operator products with a sum of powers larger than 2S can be replaced by a combination of spin operators with a maximum sum of powers not larger than 2S. This transformation is exact. All spin operators must belong to the same lattice site. By use of this procedure the consideration of single-ion anisotropies and the investigation of the magnetic reorientation within a Green's function theory are facilitated. Furthermore, it may be useful for the study of time dependent magnetic properties within the ultrashort (fsec) time domain.Comment: 11 pages, 1 table, uses rotatin

Multipotency of Adult Hippocampal NSCs In Vivo Is Restricted by Drosha/NFIB

Adult neural stem cells (NSCs) are defined by their inherent capacity to self-renew and give rise to neurons, astrocytes, and oligodendrocytes. In vivo, however, hippocampal NSCs do not generate oligodendrocytes for reasons that have remained enigmatic. Here, we report that deletion of Drosha in adult dentate gyrus NSCs activates oligodendrogenesis and reduces neurogenesis at the expense of gliogenesis. We further find that Drosha directly targets NFIB to repress its expression independently of Dicer and microRNAs. Knockdown of NFIB in Drosha-deficient hippocampal NSCs restores neurogenesis, suggesting that the Drosha/NFIB mechanism robustly prevents oligodendrocyte fate acquisition in vivo. Taken together, our findings establish that adult hippocampal NSCs inherently possess multilineage potential but that Drosha functions as a molecular barrier preventing oligodendrogenesis

Neutron skin of 208^{208}Pb from Coherent Pion Photoproduction

Information on the size and shape of the neutron skin on $^{208}$Pb has been extracted from coherent pion photoproduction cross sections measured using the Crystal Ball together with the Glasgow tagger at the MAMI electron beam facility. On exploitation of an interpolated fit of a theoretical model to the measured cross sections the half-height radius and diffuseness of the neutron distribution are found to be 6.70$\pm 0.03(stat)$ fm and 0.55$\pm 0.01(stat)$$^{+0.02}_{-0.03}(sys)$ fm respectively, corresponding to a neutron skin thickness $\Delta r_{np}$=0.15$\pm 0.03(stat)$$^{+0.01}_{-0.03}(sys)$ fm. The results give the first successful extraction of a neutron skin with an electromagnetic probe and indicate the skin of $^{208}$Pb has a halo character. The measurement provides valuable new constraints on both the structure of nuclei and the equation of state for neutron-rich matter.Comment: 4 figures 5 pages. Version submitted to journal. Includes additional studies of systematic effects in the extracted diffuseness, which led to a small increase in the quoted systematic error. These additional studies are discussed in the revised manuscript. Also includes minor editorial improvements to the tex