27 resultados para D31
Resumo:
Relative Einkommensunterschiede lösen innerhalb einer Referenzgruppe oftmals Neid aus und beeinflussen damit die individuelle Leistungsbereitschaft. In der ökonomischen Forschung ist bislang dieser Zusammenhang wenig untersucht worden. Unser Beitrag analysiert den Einfluss von relativen Einkommensunterschieden auf die Leistung von Fußballprofis der deutschen Bundesliga. Insgesamt werden 1040 Spieler über einen Zeitraum von 8 Spielzeiten zwischen 1995 und 2004 untersucht. Relative Einkommensunterschiede zwischen Mannschaftskollegen erweisen sich als entscheidender Einfluss auf die individuelle Leistung der Spieler. Eine Verschlechterung in der relativen Einkommensposition vermindert ceteris paribus die individuelle Leistungsbereitschaft. Eine höhere Einkommensungleichheit verstärkt solche positionsbedingten Externalitäten. Relative income differences are likely to lead to envy within a reference group. Envy in turn influences social behavior and individual performance. While positional concerns are apparent in daily life, empirical evidence is rare in the economic literature. This paper investigates the impact of the relative income position on individuals’ performance or productivity. As „performance“ is difficult to measure we turn to soccer players whose performance has been well documented. The broad sample covers eight seasons of the German premier soccer league (Bundesliga) between 1995 and 2004, and includes 1040 players, a salary proxy and several performance variables. The results show that player performance is strongly affected by relative income position. A disadvantage in the relative income position reduces productivity. The larger the income differences within a team, the stronger are the effects of positional concern. Team composition also significantly affects behaviour.
Resumo:
K0.5La0.5Bi2Nb2O9, a relaxor, was synthesized and the structural studies confirmed it to be an n = 2 member of the Aurivillius oxides. The ½{h00} and ½{hk0} types of superlattice reflections in the electron diffraction patterns reflected the presence of ordered polar regions. A broad dielectric peak with frequency dependent dielectric maximum temperature was observed. The dielectric relaxation obeyed the Vogel-Fulcher relation wherein Ea = 0.04 eV, Tf = 428 K,and ωo = 1010 Hz. The diffuseness parameter γ = 2.003 established the relaxor nature and it was attributed to the A-site cationic disorder. The piezoelectric d31 coefficient was 0.5 pC/N at 300 K and 2 pC/N at 480 K.
Resumo:
The objective of this work is to confirm the possibility of utilization of PolyVinyliDeneFlouride (PVDF) films in MEMS based microactuator for microjet applications. A membrane type microactuator is designed, developed, packaged and tested. The microactuator consists of PVDF film attached to thin Silicon diaphragm. As the voltage difference is applied across it, due to the piezoelectric behaviour, it deforms primarily in d31 mode, which in turn deflects the diaphragm. Using finite element methods, coupled field analysis is carried out to optimize the dimensions of the actuator with respect to the output force and input voltage. A cavity with a square diaphragm of 1mm×1mm×5μm is realized using standard microfabrication technique. 50μm thick PVDF film, cut with special dicing saw, is glued inside the metalized cavity using low stress, conductive, room temperature cured epoxy. The 3mm×3mm×0.675mm actuator die is packaged using Chip-On-Board technique in conjunction with low temperature soldering for taking the connections. The micro-actuator is tested in both actuation and sensing mode. The developed actuator is proposed to use with micro nozzle to study the utilization in drug delivery system.
Resumo:
运动目标跟踪技术是未知环境下移动机器人研究领域的一个重要研究方向。该文提出了一种基于主动视觉和超声信息的移动机器人运动目标跟踪设计方法,利用一台SONY EV-D31彩色摄像机、自主研制的摄像机控制模块、图像采集与处理单元等构建了主动视觉系统。移动机器人采用了基于行为的分布式控制体系结构,利用主动视觉锁定运动目标,通过超声系统感知外部环境信息,能在未知的、动态的、非结构化复杂环境中可靠地跟踪运动目标。实验表明机器人具有较高的鲁棒性,运动目标跟踪系统运行可靠。
Resumo:
利用SONYEV-D31摄像机和自主研发的摄像机控制模块,构建了一套主动视觉子系统,并将该子系统应用于RIRA-II型移动机器人上,实现了移动机器人运动目标自动跟踪功能。RIRA-II移动机器人采用了由一组分布式行为模块和集中命令仲裁器组成的基于行为的分布式控制体系结构。各行为模块基于领域知识通过反应方式产生投票,由仲裁器产生动作指令,机器人完成相应的动作。在设置了障碍、窄通道以及模拟墙体的复杂环境下进行运动目标跟踪实验,实验表明运动目标跟踪系统运行可靠,具有较高的鲁棒性。
Resumo:
Pathogenic bacteria may modify their surface to evade the host innate immune response. Yersinia enterocolitica modulates its lipopolysaccharide (LPS) lipid A structure, and the key regulatory signal is temperature. At 21°C, lipid A is hexa-acylated and may be modified with aminoarabinose or palmitate. At 37°C, Y. enterocolitica expresses a tetra-acylated lipid A consistent with the 3'-O-deacylation of the molecule. In this work, by combining genetic and mass spectrometric analysis, we establish that Y. enterocolitica encodes a lipid A deacylase, LpxR, responsible for the lipid A structure observed at 37°C. Western blot analyses indicate that LpxR exhibits latency at 21°C, deacylation of lipid A is not observed despite the expression of LpxR in the membrane. Aminoarabinose-modified lipid A is involved in the latency. 3-D modelling, docking and site-directed mutagenesis experiments showed that LpxR D31 reduces the active site cavity volume so that aminoarabinose containing Kdo(2)-lipid A cannot be accommodated and, therefore, not deacylated. Our data revealed that the expression of lpxR is negatively controlled by RovA and PhoPQ which are necessary for the lipid A modification with aminoarabinose. Next, we investigated the role of lipid A structural plasticity conferred by LpxR on the expression/function of Y. enterocolitica virulence factors. We present evidence that motility and invasion of eukaryotic cells were reduced in the lpxR mutant grown at 21°C. Mechanistically, our data revealed that the expressions of flhDC and rovA, regulators controlling the flagellar regulon and invasin respectively, were down-regulated in the mutant. In contrast, the levels of the virulence plasmid (pYV)-encoded virulence factors Yops and YadA were not affected in the lpxR mutant. Finally, we establish that the low inflammatory response associated to Y. enterocolitica infections is the sum of the anti-inflammatory action exerted by pYV-encoded YopP and the reduced activation of the LPS receptor by a LpxR-dependent deacylated LPS.
Resumo:
The REsearch on a CRuiser Enabled Air Transport Environment (RECREATE) project is considers the introduction and airworthiness of cruiser-feeder operations for civil aircraft. Cruiser-feeder operations are investigated as a promising pioneering idea for the air transport of the future. The soundness of the concept of cruiser-feeder operations for civil aircraft can be understood, taking air-to-air refueling operations as an example. For this example, a comprehensive estimate of the benefits can be made, which shows a fuel burn reduction potential and a CO2 emission reduction of 31% for a typical 6000 nautical miles flight with a payload of 250 passengers. This reduction potential is known to be large by any standard. The top level objective of the RECREATE project is to demonstrate on a preliminary design level that cruiser-feeder operations (as a concept to reduce fuel burn and CO2 emission levels) can be shown to comply with the airworthiness requirements for civil aircraft. The underlying Scientific and Technological (S&T) objectives are to determine and study airworthy operational concepts for cruiser-feeder operations, and to derive and quantify benefits in terms of CO2 emission reduction but also other benefits.
Work Package (WP) 3 has the objective to substantiate the assumed benefits of the cruiser/feeder operations through refined analysis and simulation. In this report, initial benefits evaluation of the initial RECREATE cruiser/feeder concepts is presented. The benefits analysis is conducted in delta mode, i.e. comparison is made with a baseline system. Since comparing different aircraft and air transport systems is never a trivial task, appropriate measures and metrics are defined and selected first. Non-dimensional parameters are defined and values for the baseline system derived.
The impact of cruiser/feeder operations such as air-to-air refueling are studied with respect to fuel-burn (or carbon-dioxide), noise and congestion. For this purpose, traffic simulations have been conducted.
Cruiser/feeder operations will have an impact on dispatch reliability as well. An initial assessment of the effect on dispatch reliability has been made and is reported.
Finally, a considerable effort has been made to create the infrastructure for economic delta analysis of the cruiser/feeder concept of operation. First results of the cost analysis have been obtained.
Resumo:
Selective degradation of organic matter in sediments is important for reconstructing past environments and understanding the carbon cycle. Here, we report on compositional changes between and within lipid classes and kerogen types (represented by palynomorph groups) in relation to the organic matter flux to the sea floor and oxidation state of the sediments since the early Holocene for central Eastern Mediterranean site ABC26. This includes the initially oxic but nowadays anoxic presapropelic interval, the still unoxidised lower part of the organic rich S1 sapropel, its postdepositionally oxidised and nowadays organic-poor upper part as well as the overlying postsapropelic sediments which have always been oxic. A general ~ 2.3 times increase in terrestrial and marine input during sapropel formation is estimated on the basis of the total organic carbon (TOC), pollen, spore, dinoflagellate cyst, n-alkane, n-alkanol and n-alkanoic acid concentration changes in the unoxidised part of the sapropel. The long-chain alkenones, 1,15 diols and keto-ols, loliolides and sterols indicate that some plankton groups, notably dinoflagellates, may have increased much more. Apart from the terrestrial and surface water contributions to the sedimentary organic matter, anomalous distributions and preservation of some C23-C27 alkanes, alkanols and alkanoic acids have been observed, which are interpreted as a contribution by organisms living in situ. Comparison of the unoxidised S1 sapropel with the overlying oxidised sapropel and the organic matter concentration profiles in the oxidised postsapropelic sediments demonstrates strong and highly selective aerobic degradation of lipids and palynomorphs. There seems to be a fundamental difference in degradation kinetics between lipids and pollen which may be possibly related with the absence of sorptive preservation as a protective mechanism for palynomorph degradation. The n-alkanes, Impagidinium, and Nematosphaeropsis are clearly more resistant than TOC. The n-alkanols and n-carboxylic acids are about equally resistant whereas the pollen, all other dinoflagellate cysts and other lipids appear to degrade considerably faster, which questions the practice of normalising to TOC without taking diagenesis into account. Selective degradation also modifies the relative distributions within lipid classes, whereby the longer-chain alkanes, alcohols and fatty acids disappear faster than their shorter-chain equivalents. Accordingly, interpretation of lipid and palynomorph assemblages in terms of pre- or syndepositional environmental change should be done carefully when proper knowledge of the postdepositional preservation history is absent. Two lipid-based preservation proxies are tested the diol-keto-ol oxidation index based on the 1,15C30 diol and keto-ols (DOXI) and the alcohol preservation index (API) whereby the former seems to be the most promising.
Resumo:
The monograph summarizes materials on geology and deep structure of the Central Atlantic fracture zones. These materials have been obtained during eight expeditions of R/V ''Akademik Nikolaj Strakhov''. The studies have been based on the integrated geological approach. As a result, many new tectonic, magmatic, metallogenic and historical-geological features of these phenomenal structures of the deep ocean have been revealed.