1,725,133 research outputs found
Glücksmarke, Johanna, Josephine, 8208
No full textGLÜCKSMARKE, JOHANNA, JOSEPHINE, 8208
Glücksmarke, Johanna, Josephine, 8208 ( -
Conjugated copolymers by Horner‐Emmons polycondensation and electroluminescence characteristics
No full textFour types of conjugated polymers, poly(MEHPV‐PV), poly(MEHPV‐BPV), poly(MEHPV‐AV) and poly(PZV‐AV) were synthesized by Horner‐Emmons reaction using potassium tert‐butoxide. The Horner‐Emmons reaction gave electroluminescent(EL) copolymers in good yield. Of the EL copolymers synthesized, poly(PZV‐AV) containing phenothiazinylene vinylene and anthrylene vinylene as repeat unit exhibited red color in the light emitting diode(LED) which was very close to the NTSC standard red. Besides, double layer LED made with Alq3 electron transport layer exhibited both enhanced emission intensity and efficiency compared to the single layer LED.clos
Excitation‐Power Dependence of the Near Band‐Edge PL Spectra of CdMnTe with High Mn Concentrations
No full textTemperature and excitation power dependences of photoluminescence (PL) measurements were studied for the CdMnTe crystal grown by the vertical Bridgman method. The near band‐edge and intra‐Mn2+Mn2+ emissions were investigated as a function of temperature. The observed band‐edge peak of the PL spectrum showed a clear blue‐shift with decreasing temperature. However, the peak energy of the intra‐Mn2+Mn2+ transition did not decrease monotonically with changing temperature, as can be seen above 70 K. With increasing the excitation power, the intensity of the emission peak was increased.ope
Close‐to‐practice investigations of heterogeneously catalyzed syngas conversions in slurry and fixed‐bed reactor systems
No full textS.690-695In der Grundlagenforschung wird die Testung heterogener Katalysatoren normalerweise mit sehr kleinen Probenmengen durchgeführt. Eine Übertragung der ermittelten Ergebnisse hinsichtlich Produktivität und Standzeit auf den technischen Maßstab ist nur sehr eingeschränkt möglich. Es wurde ein neues praxisnahes Testsystem für heterogene Katalysatoren entwickelt. Es kann sowohl in Festbett-Fahrweise als auch in Slurry-Fahrweise in einem weiten Temperatur- und Druckbereich betrieben werden. Das System wurde für die Synthese höherer Alkohole und die einstufige Dimethylether-Synthese erfolgreich eingesetzt.In fundamental heterogeneous catalyst development, testing is usually performed with rather small amounts of catalyst. Transferring the results in terms of performance and catalyst lifetime to industrial relevant pilot‐scale is hardly feasible. Thus, a new modular test system has been developed which allows large‐scale testing of heterogeneous catalysts in fixed‐bed or slurry mode, enabling a wide range of test conditions with regard to particle size, gas composition, pressure, and reaction temperature. The test system has been used for higher alcohol synthesis and one‐step dimethyl ether synthesis.90Nr.
Charakterisierung von quasi‐stationären Temperaturfeldern beim Laserstrahlschweißen durch Infrarotthermographie
No full textS.1283-1289In this work, high‐speed thermography is shown to effectively capture quasi‐stationary temperature fields during the laser welding of steel plates. This capability is demonstrated for two cases, with one involving the addition of a ferritic‐bainitic filler wire, and the other involving the addition of a low‐transformation‐temperature (LTT) filler wire. The same welding parameters are used in each case, but the temperature fields differ, with the spacing between isotherms being greater in the case where the low‐transformation‐temperature filler material is added. This observation is consistent with the differences in the extent of the heat‐affected zone in each sample, and the shape of the weld pool ripples on the weld bead surfaces. The characterization of temperature fields in this way can greatly assist in the development of novel methods for reducing residual stresses, such as the application of low‐transformation‐temperature filler materials through partial‐metallurgical injection (PMI). This technique reduces or eliminates tensile residual stresses by controlling the temperature fields so that phase transformations take place at the optimum times, and success can only be guaranteed through precise knowledge of the temperature fields in the vicinity of the welding heat source in real time.In dieser Arbeit wird Hochgeschwindigkeits‐Thermographie zur effektiven Dokumentation quasi‐stationärer Temperaturfelder während des Laserstrahlschweißens von Stahl vorgestellt. Gezeigt wird dies am Beispiel von zwei repräsentativen Schweißungen, wobei einerseits ein ferritsch‐bainitischer Zusatzdraht und andererseits ein Low‐Transformation‐Temperature‐ (LTT) Zusatzdraht verwendet wird. In beiden Fällen werden die gleichen Schweißparameter verwendet. Im Vergleich wird eine merkliche Abweichung der Temperaturfelder deutlich. Bei Low‐Transformation‐Temperature‐Zusatzdraht vergrößern sich die Abstände zwischen den Isothermen. Die Beobachtungen sind konsistent mit der Ausdehnung der Wärmeeinflusszonen in beiden Proben sowie der Ausbildung der Nahtoberraupe. Die Charakterisierung der Temperaturfelder kann auf diesem Weg die Entwicklung neuartiger Methoden zur Eigenspannungsreduzierung unterstützen, wie beispielsweise die Applikation von Low‐Transformation‐Temperature und Anwendung der partiellen metallurgischen Injektion (PMI). Diese Technologie reduziert Zugeigenspannungen durch gezieltes Aufprägen von Wärmefelder, so dass die martensitische Phasenumwandlung zu einem optimalen Zeitpunkt abläuft. Eine Voraussetzung zur erfolgreichen Anwendung sind präzise Kenntnisse über die Temperaturfelder in der direkten Umgebung der Schweißwärmequelle in Echtzeit.48Nr.1
Inkjet Printing of Self‐Supporting and Self‐Contained Structured Objects Onto Liquid Surfaces
No full textArt.1900227, 11 S.Some applications in miniaturized fabrication like valves or force sensors require self‐supporting structures. These may be generated on top of a solid substrate and separated from it afterwards, but this separation is an additional manufacturing step and may stress the structure. Therefore, it may be of advantage to create the desired objects directly on top of a liquid. Here, it is shown that self‐supporting and self‐contained structures including lines of defined width, full tone squares and delicate structures with non‐uniform line width, edges and openings can be prepared by inkjet printing of a photo‐curable ink onto a water surface followed by irradiation with ultraviolet light and lift‐off. To make this feasible, convection, spreading, and dewetting of the ink from the water surface has to be suppressed by controlling the timing of the irradiation, the mobility of the water surface and the long and short range interactions between the printed ink and the water substrate. These tasks may be achieved via addition of soluble amphiphiles or via spreading of water insoluble amphiphiles or hydrophobized particles onto the water surface prior to printing. Best results are obtained by printing the desired structures onto a water surface that bears a monolayer of hydrophobized particles.21Nr.
Repeatability of Phase‐Resolved Functional Lung (PREFUL)‐MRI Ventilation and Perfusion Parameters in Healthy Subjects and COPD Patients
No full textS-915-927Background: Free‐breathing phase‐resolved functional lung (PREFUL)‐MRI may be useful for treatment monitoring in chronic obstructive pulmonary disease (COPD) patients with dyspnea. PREFUL test-retest reliability is essential for clinical application. Purpose: To measure the repeatability of PREFUL‐MRI ventilation (V) and perfusion (Q) parameters. Study Type: Retrospective and prospective. Population: A total of 28 COPD patients and 57 healthy subjects. Field Strength/Sequence. 1.5T MRI/2D spoiled gradient echo imaging. Assessment: V and Q lung parameter maps based on three coronal slices were obtained at baseline and after 14 days (COPD patients) or after a short pause outside the scanner (healthy subjects). Regional ventilation (RVent) and imaging flow volume loops by cross‐correlation (ccVent) were quantified. Q was normalized to the signal of the main pulmonary artery (QN) and quantified (QQuant). Pulmonary pulse wave transit time (pPTT), voxel‐by‐voxel (regional), and whole lung (global) ventilation defect percentage based on RVent (VDPRVent) and ccVent (VDPccVent), perfusion defect percentage (QDP), and ventilation/perfusion match based on RVent (VQMRVent) and ccVent (VQMccVent) were calculated. Statistical Tests: Regional V and Q were analyzed globally for each subject. Each parameter's median of scans 1 and 2 were assessed by Wilcoxon sign rank test. A parameter's repeatability was analyzed by Bland-Altman analyses, coefficients of variation, intraclass correlation coefficients (ICC), and power calculations. The regional voxel repeatability was examined by calculating the Sørensen-Dice coefficient. Results: There was no bias and no significant differences between the first and second MRI for any parameters (P > 0.05). Coefficient of variation ranged from 2.26% (ccVent) to 19.31% (QDP), ICC from 0.93 (QDP) to 0.60 (pPTT), the smallest detectable difference was 0.002 ccVent. Regional comparison showed the highest overlap (84%) in VDPRVent in healthy voxels and the lowest (53%) in VDPccVent defect voxels. Data Conclusion: V and Q PREFUL‐MRI parameters were repeatable over two scan sessions in both healthy controls and COPD patients.53Nr.
An Analysis of Investment Decisions for Energy‐Efficient Renovation of Multi‐Family Buildings
No full text, Final Repor
Functional Inequalities Associated with Jordan‐von Neumann‐Type Additive Functional Equations
No full text We prove the generalized Hyers‐Ulam stability of the following functional inequalities: , , in the spirit of the Rassias stability approach for approximately homomorphisms.</p
The Discovery of a Novel Chemical Scaffold that Binds Dengue Virus Non‐structural Protein 5
Full text linkDengue viruses (DENV) are mosquito‐borne flaviviruses that pose a continued and growing threat to global health. There are estimated to be 390 million DENV infections each year, and because there is no vaccine or approved therapeutic treatment, developing a small‐molecule treatment is imperative. Possible small‐molecule drug therapies for DENV could be immune system modulators, inhibitors of DENV‐required host factor, or inhibitors of a viral gene product. In this study, we chose to take the latter approach and focused our drug discovery efforts on the most highly conserved flaviviral protein, non‐structural protein 5 (NS5). NS5 contains two major domains, each with different enzymatic activities. The N‐terminus has methyltransferase activity, and the C terminus, an RNA‐dependent RNA polymerase (RdRp). The activities of both domains are purine‐dependent, and therefore both domains contribute to the purine‐binding properties of NS5. Inhibition of either of these domains in NS5 results in inadequate propagation of DENV, and the purine‐binding domains present ideal drug targets for disrupting these activities. These factors make NS5 protein an ideal candidate target for our small‐molecule library screen.A high‐throughput fluorescence‐based screen was employed to identify anti‐DENV compounds based on their ability to competitively bind NS5. The screen was performed by binding green fluorescent protein NS5 fusion protein (GFP‐NS5) to immobilized ATP resin, and then performing parallel elutions using over 3,000 distinct compounds. One compound in particular, HS‐205020, was able to competitively elute GFP‐NS5 from the ATP resin and also exhibited antiviral activity in both the U937+DCSIGN human monocyte cell line and BHK‐21 cells. Additionally, HS‐205020 was able to inhibit DENV NS5 RNA polymerase activity in vitro. HS‐205020 is chemically distinct from the majority of previously reported NS5 inhibitors, which are nucleoside analogs that can cause severe toxicity in animal studies. In contrast, over the concentration range that produced anti‐DENV effects, HS‐205020 showed comparable viabilities to ribavirin, an FDA approved hepatitis C virus (HCV) therapeutic. These findings support HS‐205020 as a potential dengue antiviral candidate, and its chemical scaffold represents as an ideal starting compound for future structure‐activity relationship studies.</p
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