Experimentelle und numerische Untersuchung des Tropfenaufstiegs

The results of an experimental and numerical investigation of an organic toluene droplet rising in a continuous aqueous phase are presented. The experiments were carried out in a small‐scale, high‐speed measuring unit. The numerical simulations were performed with the aid of the level set method implemented in the commercial CFD tool COMSOL Multiphysics 3.3a. Both measured and simulated terminal velocities are found to be in excellent agreement and match recent results. Moreover, the deviation from the spherical form is captured very well for different droplet sizes. Based on the experimental and numerical data obtained, an improvement of an existing terminal velocity correlation is suggested.     

框架结构弹塑性分析的一种有效数值方法

框架结构的不完全弹塑性分析是一个非线性过程,按照假定的加载模式,利用荷载因子进行逐步加载。基于力学和数值方法,研究框架结构的极限承载力和变形能力。假定材料为理想弹塑性,并利用零长度塑性铰模拟塑性行为。该方法基于增量方程,类似于求解两个连续塑性铰之间的凸二次参数规划问题。利用虚荷载因子将凸二次参数规划转化为凸二次规划,并使用标准算法求解凸二次规划问题,可满足出现塑性铰的要求并自动判别塑性。该方法起初仅适用于纯弯作用,后延伸至弯矩-轴力共同作用。分别分析单调、变化、循环加载作用下的算例。整个过程稳定、可靠、高效,并比基于直接刚度法的交替位移方法更省时。     

A model for European Biogenic Volatile Organic Compound emissions: Software development and first validation

A grid-oriented Biogenic Emission Model (BEM) has been developed to calculate Non-Methane Volatile Organic Compound (NMVOC) emissions from vegetation in high spatial and temporal resolutions. The model allows the emissions calculation for any modeling domain covering Europe on the basis of: 1) the U.S. Geological Survey 1-km resolution land-use database, 2) a land-use specific, monthly isoprene, monoterpene and Other Volatile Organic Compound (OVOC) emission potentials and foliar biomass densities database, 3) temperature and solar radiation data provided by the mesoscale meteorological model MM5. The model was applied for Europe in 30-km spatial resolution for the year 2003. The European total emissions for 2003 consist of 33.0% isoprene, 25.5% monoterpenes and 41.5% OVOC. BEM results are compared with those from the well-documented global Model of Emissions of Gases and Aerosols from Nature (MEGAN). The BEM total emissions compare well with the MEGAN ones. In July 2003, the results of both models agree within a factor of 1.2 for total isoprene emissions and within a factor of 2 for total monoterpene emissions. The comparison of the spatial distributions of the July 2003 isoprene and monoterpene emissions calculated with BEM and MEGAN shows that, in the greater part of the study area, the differences are below the current uncertainty limit for the estimation of spatially-resolved biogenic VOC emissions in Europe being equal to about ±600 kg km^?2 month^?1. Differences that are above this limit are found mainly in the eastern European countries for isoprene and in the Mediterranean countries for monoterpenes.     

Optimization of single-phase induction motors-part II: magnetic and torque performance under optimal control

The magnetic and torque performance of a capacitor-run single-phase induction motor operated at constant torque under the optimal efficiency control, as presented in Part I, is analyzed. The magnetic field analysis demonstrates that magnetic saturation is considerably decreased with optimal efficiency control. Although triac-based optimal voltage controller introduces voltage and current harmonics, torque pulsations and acoustic noise are reduced due to magnetic flux weakening. The reduction of torque pulsations and acoustic noise is considerable in the low torque region where significant energy savings are also achieved. Selected calculated and experimental results are presented to validate the theoretical considerations and the resulting improvements.     

A survey on multivariate adaptive control charts: Recent developments and extensions

In the world of business, quality improvement is of high importance for the manufacturing industries. Statistical process control via control charts provides an online monitoring of the product's characteristic. The adaptive feature is being widely used in the design parameters of a control chart, which allows at least one of them to change during the process monitoring. Specifically, a control chart is considered adaptive if at least one of the chart's parameters (sample size, sampling interval, or control limit coefficient) is allowed to change in real time on the basis of the actual values of the sample statistics. In this paper, recent developments in the design of multivariate adaptive control schemes are presented and discussed.     

Investigation of NiO<Subscript>x</Subscript>-hole transport layers in triple cation perovskite solar cells

Perovskite solar cells with a planar p-i-n device structure offer easy processability at low temperatures, suitable for roll-to-roll fabrication on flexible substrates. Herein we investigate different hole transport layers (solution processed NiO_x, sputtered NiO_x, PEDOT:PSS) in planar p-i-n perovskite solar cells using the triple cation lead halide perovskite Cs_0.08(MA_0.17FA_0.83)_0.92Pb(I_0.83Br_0.17)₃ as absorber layer. Overall, reproducible solar cell performances with power conversion efficiencies up to 12.8% were obtained using solution processed NiO_x as hole transport layer in the devices. Compared to that, devices with PEDOT:PSS as hole transport layer yield efficiencies of approx. 8.4%. Further improvement of the fill factor was achieved by the use of an additional zinc oxide nanoparticle layer between the PC₆₀BM film and the Ag electrode.     

Late‐onset Pompe's disease in a hemodialysis patient: A first case report

A 37‐year‐old hemodialysis patient appeared with unusual somnolence during 2 successive hemodialysis sessions. Blood gas analysis revealed hypercapnic respiratory failure and spirometry restrictive lung disease. After exclusion of other causes of restrictive lung disease with chest CT‐scan and cerebrum MRI, electrophysiological study revealed myopathy. Because besides lordosis and limb‐girdle gait the patient was ambulant the possibility of late‐onset Pompe's disease was set and confirmed with evaluation of α‐glucosidase activity and genetic analysis. Enzyme replacement therapy (ERT) with aglucosidase alfa was started. Due to inaccessibility of veins in the arm without the arteriovenous fistula, during the last 1 year, the patient received the ERT through the venous line of the hemodialysis circuit. Three years later the patient remains ambulant without the need of any assistant device and preserved his pulmonary function. This is the first described case of late‐onset Pompe's disease in a hemodialysis patient treated with ERT.     

Flexible least squares for temporal data mining and statistical arbitrage

A number of recent emerging applications call for studying data streams, potentially infinite flows of information updated in real-time. When multiple co-evolving data streams are observed, an important task is to determine how these streams depend on each other, accounting for dynamic dependence patterns without imposing any restrictive probabilistic law governing this dependence. In this paper we argue that flexible least squares (FLS), a penalized version of ordinary least squares that accommodates for time-varying regression coefficients, can be deployed successfully in this context. Our motivating application is statistical arbitrage, an investment strategy that exploits patterns detected in financial data streams. We demonstrate that FLS is algebraically equivalent to the well-known Kalman filter equations, and take advantage of this equivalence to gain a better understanding of FLS and suggest a more efficient algorithm. Promising experimental results obtained from a FLS-based algorithmic trading system for the S&P 500 Futures Index are reported.     

Visual data mining modeling techniques for the visualization of mining outcomes

The visual senses for humans have a unique status, offering a very broadband channel for information flow. Visual approaches to analysis and mining attempt to take advantage of our abilities to perceive pattern and structure in visual form and to make sense of, or interpret, what we see. Visual Data Mining techniques have proven to be of high value in exploratory data analysis and they also have a high potential for mining large databases. In this work, we try to investigate and expand the area of visual data mining by proposing new visual data mining techniques for the visualization of mining outcomes.     

Asymmetric Dimethylarginine as a Surrogate Marker of Endothelial Dysfunction and Cardiovascular Risk in Patients with Systemic Rheumatic Diseases

The last few decades have witnessed an increased life expectancy of patients suffering with systemic rheumatic diseases, mainly due to improved management, advanced therapies and preventative measures. However, autoimmune disorders are associated with significantly enhanced cardiovascular morbidity and mortality not fully explained by traditional cardiovascular disease (CVD) risk factors. It has been suggested that interactions between high-grade systemic inflammation and the vasculature lead to endothelial dysfunction and atherosclerosis, which may account for the excess risk for CVD events in this population. Diminished nitric oxide synthesis—due to down regulation of endothelial nitric oxide synthase—appears to play a prominent role in the imbalance between vasoactive factors, the consequent impairment of the endothelial hemostasis and the early development of atherosclerosis. Asymmetric dimethylarginine (ADMA) is one of the most potent endogenous inhibitors of the three isoforms of nitric oxide synthase and it is a newly discovered risk factor in the setting of diseases associated with endothelial dysfunction and adverse cardiovascular events. In the context of systemic inflammatory disorders there is increasing evidence that ADMA contributes to the vascular changes and to endothelial cell abnormalities, as several studies have revealed derangement of nitric oxide/ADMA pathway in different disease subsets. In this article we discuss the role of endothelial dysfunction in patients with rheumatic diseases, with a specific focus on the nitric oxide/ADMA system and we provide an overview on the literature pertaining to ADMA as a surrogate marker of subclinical vascular disease.