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91.
Prof. Dr.-Ing. habil. Dominik Surek Dipl.-Ing. Hubertus Galinsky 《Forschung im Ingenieurwesen》1995,61(5):117-128
Zusammenfassung Seitenkanalverdichter unterliegen trotz ihrer geringen Druckverh?ltnisse im Teillastbereich erheblichen thermischen Belastungen.
Dadurch steigt nicht nur die Verdichtungsendtemperatur und die Maschinenbelastung, sondern mit steigender Maschinentemperatur
erfolgt auch eine erhebliche Aufheizung des Gases bereits im Eintrittsbereich, wodurch die Arbeitsübertragung beeinflu?t wird.
Die Resultate experimenteller Untersuchungen zeigen, da? die Aufheizung des Gases besonders im Eintrittsbereich des Seitenkanals
erfolgt und dadurch die Arbeitsübertragung im vorderen Bereich stark verlustbehaftet erfolgt. Die Folge davon sind sehr hohe
Polytropenexponenten bei gro?en Druckverh?ltnissen im Teillastbereich, die zu einer gro?en W?rmezufuhr an das Gas führen und
den Wirkungsgrad der Maschinen mindern. 相似文献
92.
Prof. Dr.-Ing habil. Dominik Surek Prof. Dr.-Ing. habil. Gerd Grabow Dr.-Ing. H. H. Henning 《Forschung im Ingenieurwesen》1995,61(9):233-240
Zusammenfassung Im Resonator von Laseranlagen werden ca. 20% der zugeführten Energie für den Laserstrahl genutzt. 80% der zugeführten Gesamtenergie
werden mit dem Lasergas ungenutzt aus dem Resonator in den nachfolgenden W?rmeübertrager abgeführt. Um den Anlagenwirkungsgrad
von Laseranlagen zu erh?hen, soll die ungenutzte Austrittsenergie aus dem Resonator in einer nachgeschalteten Entspannungsturbine
in mechanische Energie umgesetzt werden, die zum Antrieb des Lasergasverdichters genutzt wird. Dadurch kann der Verdichter
mit der vorhandenen Proze?energie angetrieben werden und der Anlagenwirkungsgrad vonη
A
bis 0,20 aufη
A
bis 0,34 erh?ht werden. Durch thermodynamische Proze?untersuchungen werden die erreichbaren Wirkungsgradsteigerungen von
Laseranlagen ausgewiesen und die optimalen Parameterbereiche für die Druck-und Temperaturverh?ltnisse ermittelt. Das Leistungsverh?ltnis
der gewonnenen Turbinenleistung zur notwendigen Verdichterleistung wird angegeben. 相似文献
93.
Shan Jiang Thammanoon Sreethawong Serina Siew Chen Lee Michelle Bee Jin Low Khin Yin Win Agata Maria Brzozowska Serena Lay‐Ming Teo G. Julius Vancso Dominik Jaczewski Ming‐Yong Han 《Advanced Materials Interfaces》2015,2(3)
With the ban of tributyltin, copper‐based biocides are now widely used in antifouling coatings as the major active ingredients. Given the past experience of heavy‐metal accumulation in harbors with limited water exchange, there is a significant interest in developing copper materials that greatly reduce the amount of copper ions released into marine surroundings. In this paper, copper nanowires (NWs) encapsulated in polymer matrices are investigated as the means to control the release of copper ions and to achieve a long‐lasting antifouling effect. Very long CuNWs with high aspect ratio in organic solution are drop‐coated onto substrates to fabricate uniform thin films. They are then incorporated into an elastomeric polydimethylsiloxane (PDMS) matrix. A small amount of CuNWs in PDMS can inhibit barnacle cyprid settlement, while it exhibits low mortality to cyprids and nauplii present in the surrounding seawater environment. The low levels of copper released after 50 days suggest that the intersecting and interconnected CuNWs embedded in PDMS could potentially release copper ions continuously over a few years in seawater. This approach provides a novel platform to use hybrid materials as effective marine antifouling coatings, and may be applied to fouling release materials to enhance their antifouling properties. 相似文献
94.
This paper describes the technological status of and some challenges in the manufacturing of Cu(In,Ga)Se2 (CIGS)-based solar cells on flexible polymer and metal substrates. Substrate characteristics such as thermal expansion properties and stability, surface roughness, or substrate composition, strongly influence growth and properties of the following layers. For example, adhesion failure, cracking, or contamination by diffusion of impurities from the substrate may occur with some substrates. Aspects of (external) sodium incorporation into CIGS are discussed for high and low CIGS deposition temperature. Low-temperature deposition processes are particularly important when polyimide substrates are used. The electrical insulation of metal foils by dielectric barriers (e.g. SiOx or Al2O3) allows the fabrication of monolithically integrated modules. A soft and selective patterning technique based on laser scribing and mask-free photolithography is described. Working modules as large as 20 cm × 30 cm were achieved with these methods. 相似文献
95.
A laser based process for the formation of a local back surface field for n-type silicon solar cells
We report on the development of a laser doping process for the formation of a local back surface field (LBSF) for n-type silicon solar cells. Local point contacts are formed by applying a laser process to a doped, passivating layer of amorphous silicon carbide (PassDop layer). The exposure to laser radiation results in local doping and opening of the passivation layer at the same time. By variation of the laser parameters and the dopant content in the layer, strength and depth of the doping can be controlled. Both parameters are varied and the formation of a LBSF structure on lifetime samples is investigated. High dopant content in the passivation layer and comparably low laser fluencies yield the best electrical results, evidencing the formation of an effective LBSF in combination with a restricted laser induced damage in the silicon crystal. 相似文献
96.
97.
Tagit O Tomczak N Jafarpour A Jańczewski D Han MY Vancso GJ Herek JL 《Nanotechnology》2011,22(26):265701
Structural and optical characterization of water soluble, thermo-responsive quantum dot/poly(N-isopropyl acrylamide) (QD/PNIPAM) hybrid particles using fluorescence correlation spectroscopy (FCS) and time-correlated single photon counting (TCSPC) measurements performed at temperatures below and above the lower critical solution temperature (LCST) of PNIPAM is reported. By increasing the temperature above the LCST, the signature of the PNIPAM chain collapse covering the QDs is revealed by FCS measurements. Despite the significant structural change, the TCSPC measurements show that the fluorescence lifetimes remain of the same order of magnitude at T > LCST. Such QD/PNIPAM hybrid particles with water solubility and robust thermo-responsive behavior at physiologically relevant temperatures are potentially useful for (bio)molecular sensing and separation applications. 相似文献
98.
Direct injection of samples on high-resolving mass spectrometers is an effective way to maximize analytical throughput and yet allow analyte discrimination in complex samples by mass-to-charge ratio. We present a platform of flow injection electrospray-time-of-flight mass spectrometry to profile small molecules in >1400 biological extracts per day at native mass resolution. We comprehensively benchmark the performance with more than 5000 injections of chemically defined standards and Escherichia coli cellular extracts obtained from miniscale cultivations. For at least 90% of tested compounds, we attain a linear response over 3 decades of concentration, interday coefficient of variation of <20%, and a mass accuracy of <0.001 amu. In polar Escherichia coli fractions, we reproducibly detected >1500 distinct ions in each mode. The accurate mass and correlation analysis enabled one to assign with good confidence 400-800 ions to electrospray derivatives of metabolites listed in the genome-wide reconstruction of Escherichia coli metabolism. Hence, we attain a coverage of about one-quarter of the total number of compounds listed in the reconstruction. Finally, we present an exemplary screen with Escherichia coli deletion mutants to show the exquisite capacity of the platform to identify lesions in primary metabolism at high throughputs. 相似文献
99.
A laboratory scale setup was used for characterization of gravitational drainage of waste activated sludge. The aim of the study was to assess how time of drainage and cake dry matter depended on volumetric load, SS content and sludge floc properties. It was demonstrated that activated sludge forms compressible cakes, even at the low pressures found in gravitational drainage. The values of specific cake resistance were two to three orders of magnitude lower than those obtained in pressure filtration. Despite the compressible nature of sludge, key macroscopic parameters such as time of drainage and cake solid content showed simple functional dependency of the volumetric load and SS of a given sludge. This suggests that the proposed method may be applied for design purposes without the use of extensive numerical modeling. The possibilities for application of this new technique are, among others, the estimation of sludge drainability prior to mechanical dewatering on a belt filter, or the application of surplus sludge on reed beds, as well as adjustments of sludge loading, concentration or sludge pre-treatment in order to optimize the drainage process. 相似文献
100.