Isolation of Failing Scan Cells through Convolutional Test Response Compaction

This paper describes a non-recursive fault diagnosis technique for scan-based designs with convolutional test response compaction. The proposed approach allows a time-efficient and accurate identification of failing scan cells using Gauss–Jordan elimination method.

Assessment of cellular oxygen gradients with a panel of phosphorescent oxygen-sensitive probes

The supply of oxygen (O(2)) to respiring tissue, cells, and mitochondria regulates metabolism, gene expression, and cell fate. Depending on the cell type and mitochondrial function, O(2) gradients between extra- and intracellular compartments may vary and play important physiological roles such as the regulation of activity of prolyl hydroxylases and adaptive responses to hypoxia. Here we present a new methodology for the analysis of localized O(2) gradients in cultures of adherent cells, using three phosphorescent Pt-porphyrin based probes with different localization. One new O(2) probe targeted to the cell membrane was developed and used together with existing MitoXpress and Nano2 probes to monitor mean pericellular (PC), extracellular (EC), and intracellular (IC) O(2) concentrations, respectively. Mouse fibroblasts and neuronal PC12 cells cultured in standard microplates were stained with probes and measured on a commercial time-resolved fluorescence reader in phosphorescence lifetime mode. Respiring cells exposed to various levels of atmospheric O(2) showed differences in oxygenation of their IC, PC, and EC compartments. Experiments with different cell numbers and modulation of respiration activity demonstrated that these gradients are dynamic and regulated by the O(2) diffusion and consumption rate. The new method facilitates the assessment of such gradients.     

High-precision isothermal titration calorimetry with automated peak-shape analysis

Isothermal titration calorimetry (ITC) is a powerful classical method that enables researchers in many fields to study the thermodynamics of molecular interactions. Primary ITC data comprise the temporal evolution of differential power reporting the heat of reaction during a series of injections of aliquots of a reactant into a sample cell. By integration of each injection peak, an isotherm can be constructed of total changes in enthalpy as a function of changes in solution composition, which is rich in thermodynamic information on the reaction. However, the signals from the injection peaks are superimposed by the stochastically varying time-course of the instrumental baseline power, limiting the precision of ITC isotherms. Here, we describe a method for automated peak assignment based on peak-shape analysis via singular value decomposition in combination with detailed least-squares modeling of local pre- and postinjection baselines. This approach can effectively filter out contributions of short-term noise and adventitious events in the power trace. This method also provides, for the first time, statistical error estimates for the individual isotherm data points. In turn, this results in improved detection limits for high-affinity or low-enthalpy binding reactions and significantly higher precision of the derived thermodynamic parameters.     

Vibrations of a vehicle excited by real road profiles

Based on experimental data obtained from the Lublin III delivery car, we have performed a vibration analysis of the vehicle suspension system. Vertical accelerations on the left and right sides of the suspension system were measured. Experiments were carried out on three types of road surfaces: (a) asphalt, (b) sett, and (c) railway cross. The acceleration signals were examined using Fourier transform, multiscale entropy analysis and continuous wavelet transform. These methods reveal the characteristics of the vibration patterns produced by the various road surface profiles. Our results can be used to assess the efficacy of a vehicle suspension system under different road conditions.     

Preparation and characterization of magnetic carbon nanomaterials bearing APTS–silica on their surface

The formation of metal-encapsulated carbon nanomaterials by using metallic catalysts (iron, cobalt, and nickel) has been studied. Moreover, these materials were coated with silica surface modified by (3-Aminopropyl)-trimethoxysilane (APTS). Each intermediate structure was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The surface morphology of silica-coated carbon nanomaterials was analyzed by scanning electron microscopy (SEM). The modified, APTS–silica surface was additionally characterized by Fourier transform infrared spectroscopy (FT-IR), elemental (EA), and thermogravimetric analysis (TGA).     

Shape design of internal cooling passages within a turbine blade

The article concerns the optimization of the shape and location of non-circular passages cooling the blade of a gas turbine. To model the shape, four Bezier curves which form a closed profile of the passage were used. In order to match the shape of the passage to the blade profile, a technique was put forward to copy and scale the profile fragments into the component, and build the outline of the passage on the basis of them. For so-defined cooling passages, optimization calculations were carried out with a view to finding their optimal shape and location in terms of the assumed objectives. The task was solved as a multi-objective problem with the use of the Pareto method, for a cooling system composed of four and five passages. The tool employed for the optimization was the evolutionary algorithm. The article presents the impact of the population on the task convergence, and discusses the impact of different optimization objectives on the Pareto optimal solutions obtained. Due to the problem of different impacts of individual objectives on the position of the solution front which was noticed during the calculations, a two-step optimization procedure was introduced. Also, comparative optimization calculations for the scalar objective function were carried out and set up against the non-dominated solutions obtained in the Pareto approach. The optimization process resulted in a configuration of the cooling system that allows a significant reduction in the temperature of the blade and its thermal stress.     

Modeling lubricant flow between thrust-bearing pads

Inlet temperature is one of the main inputs in all models for the analysis of fluid film bearing performance. At the same time, inlet temperature distribution and also oil velocity distribution at the inlet are the result of flow phenomena in the gap between the bearing pads. These phenomena are complex and in many cases further affected by any special arrangements of forced oil supply to the gap between pads. The reason for such arrangements is the more efficient introduction of externally cooled lubricant. Not many details are known about any flow phenomena in the gap between the pads and even less if the bearing is fitted with any kind of directed lubrication system. Contemporary tools of computational fluid dynamics (CFD) enable one to study the flow between bearing pads and even to build models of a whole hydrodynamic bearing. Preliminary results of modeling lubricant flow in the gap, in a bearing with a direct oil supply system will be presented in this paper. The effects of modified inlet oil temperature on some aspects of bearing performance are also presented.     

轮胎噪声与滚动阻力的相关性

低滚动阻力和低噪声是对现代轮胎的要求,其目的在于保护环境和提高车辆运行的经济性。在大多数驾驶条件下,轮胎／道路噪声是车辆行驶噪声的主要来源。社会调查显示,交通噪声环境污染对人类的影响远远大于其他任何形式的污染。轮胎滚动阻力直接影响车辆的燃油消耗,并与二氧化碳和其他废气的排放密切相关。     

Profile of fatty acids, muscle structure and shear force of musculus longissimus dorsi (MLD) in growing pigs as affected by energy and protein or protein restriction followed by realimentation

Forty-eight gilts were submitted to a 30% restriction of feed (groups F and F1) or protein intake (group P) from 90 to 118 days of age, followed by realimentation from 119 to 168 days of age. Control pigs (C) were fed during the whole experiment according to a semi ad libitum scale. During realimentation all animals were fed according to semi ad libitum scale except pigs F1 which were fed ad libitum. Six pigs from each group were slaughtered at the end of restriction and realimentation. Restriction decreased the weight of musculus longissimus dorsi (MLD) and increased shear force. Restriction of feed intake depressed MUFA concentration and increased n-6/n-3 ratio while protein restriction decreased n-6/n-3 and PUFA:SFA ratios. Structure of fibers was not affected. After realimentation MLD mass was still lower in all previously restricted pigs, shear force was the lowest in F1 pigs. Only percentage of fast twich oxidative fibers was significantly greater in F1 pigs than in others. Significant correlations between parameters investigated during the study were found.