Explicit optimal control policy and its practical application for hybrid electric powertrains

This paper presents a simplified, yet realistic, model of a hybrid electric powertrain and derives the explicit solution of the optimal energy management. The explicit solution of this optimal control problem consists of simple rules that rely on powertrain parameters only. The simplified model is validated on a more complex model relying on measured data. Finally, a causal, real-time control strategy including anti-windup is presented. This strategy relies on the optimal control of the simplified model and is successfully evaluated on the complex model that relies on measured data.     

A Thermally Responsive PDMS Composite and Its Microfluidic Applications

This paper describes a novel composite actuator for controlled liquid actuation in microsystems which is based on a thermally responsive elastomer. The composite actuator consists of expandable microspheres incorporated in a polydimethylsiloxane (PDMS) matrix and entails the merits of both PDMS and expandable microspheres. The main characteristic of the composite actuator is to expand upon heat. The expansion is irreversible and the relative volume increase is measured up to 270% of its original volume after heating to 80 degC. The composite was used to fabricate single-use microfluidic pumps and valves. We show the displacement of liquids in the range of nanoliters even against counter pressures up to 100 kPa. Moreover, liquid flow in microchannels was entirely blocked by means of the integrated valves. The valves can withstand pressures up to 140 kPa. The devices are fabricated using low-cost materials only, and the composite actuator allows using wafer-level processing. The fluidic components based on the novel composite are highly integrable and do not require external actuators     

Nutritional composition,fatty acid profile,phytochemistry and evaluation of the effects of Carya illinoinensis on diabetes

The increase in chronic diseases has arisen interest to search for alternative treatments so that people can improve their quality of life. Thus, Carya illinoinensis is the subject of the present work which aims at determining whether it has antidiabetic activity. The plant was collected and its nuts were separated from their peels, dried and grinded and incorporated into the feed, in concentration of 6% and 10%, for the treatment of animals. The centesimal composition of this diet was also determined. From the nut was also obtained the fixed oil, for the profile of fatty acids, and the 70% hydroethanolic extract for the phytochemical analysis. The results have shown that species presents hypoglycaemic effect, high fat composition of unsaturated fatty acids and the presence of some phenolic compounds, directly related to the antidiabetic activity. Therefore, the specie presente benefits that can contribute to the binomial diet/health.     

Modeling Bacterial Species: Using Sequence Similarity with Clustering Techniques

Existing studies have challenged the current definition of named bacterial species, especially in the case of highly recombinogenic bacteria. This has led to considering the use of computational procedures to examine potential bacterial clusters that are not identified by species naming. This paper describes the use of sequence data obtained from MLST databases as input for a k-means algorithm extended to deal with housekeeping gene sequences as a metric of similarity for the clustering process. An implementation of the k-means algorithm has been developed based on an existing source code implementation, and it has been evaluated against MLST data. Results point out to potential bacterial clusters that are close to more than one different named species and thus may become candidates for alternative classifications accounting for genotypic information. The use of hierarchical clustering with sequence comparison as similarity metric has the potential to find clusters different from named species by using a more informed cluster formation strategy than a conventional nominal variant of the algorithm.     

Occurrence of caffeine,saccharin, benzoic acid and sorbic acid in soft drinks and nectars in Portugal and subsequent exposure assessment

A reliable method for the determination of benzoic and sorbic acids, caffeine and saccharin in soft drink and nectars using high performance liquid chromatography and UV detection was validated. The chromatographic separation was achieved with a C18 column (250 × 4.6 mm) and one buffered mobile phase, KH₂PO₄ 0.02 M/ACN (90:10)/phosphoric acid at pH 4.2. The effluent was monitored at 220 nm.     

A chemometric study of genotypic variation in triacylglycerol composition among selected almond cultivars

Triacylglycerol composition of 10 almond cultivars grown in seven different environments was determined by high-performance liquid chromatography, and multivariate statistical techniques (principal component and cluster analysis) were used to detect and establish associations among almond cultivars. In particular, linear discriminant analysis showed that cultivars Desmayo Largueta, Masbovera, Texas, Non Pareil, Tuono, and Guara are different from each other and can be classified in different groups. This statistical approach also predicted the origin of eight hybrids produced from these cultivars. As a result, it is concluded that triacylglycerol composition in almonds can distinguish genetic from environmental effects on almond triacylglycerol composition.     

Frequency division transmission imaging and synthetic aperture reconstruction

In synthetic transmit aperture imaging only a few transducer elements are used in every transmission, which limits the signal-to-noise ratio (SNR). The penetration depth can be increased by using all transmitters in every transmission. In this paper, a method for exciting all transmitters in every transmission and separating them at the receiver is proposed. The coding is done by designing narrow-band linearly frequency modulated signals, which are approximately disjointed in the frequency domain and assigning one waveform to each transmitter. By designing a filterbank consisting of the matched filters corresponding to the excitation waveforms, the different transmitters can be decoded at the receiver. The matched filter of a specific waveform will allow information only from this waveform to pass through, thereby separating it from the other waveforms. This means that all transmitters can be used in every transmission, and the information from the different transmitters can be separated instantaneously. Compared to traditional synthetic transmit aperture (STA) imaging, in which the different transmitters are excited sequentially, more energy is transmitted in every transmission, and a better signal-to-noise-ratio is attained. The method has been tested in simulation, in which the resolution and contrast was compared to a standard synthetic transmit aperture system with a single sinusoid excitation. The resolution and contrast was comparable for the two systems. The method also has been tested using the experimental ultrasound scanner RASMUS. The resolution was evaluated using a string phantom. The method was compared to a conventional STA using both sinusoidal excitation and linear frequency modulated (FM) signals as excitation. The system using the FM signals and the frequency division approach yielded the same performance concerning both axial (of approximately equal to 3 wavelengths) and lateral resolution (of approximately equal to 4.5 wavelengths). A SNR measurement showed an increase in SNR of 6.5 dB compared to the system using the conventional STA method and FM signal excitation.     

Silica coating of polymer nanowires produced via nanoimprint lithography from femtosecond laser machined templates

In this paper we report on the fabrication of regular arrays of silica nanoneedles by deposition of a thin layer of silica on patterned arrays of polymer nanowires (or polymer nanohair). An array of high-aspect-ratio nanoscale diameter holes of depths greater than 10?μm was produced at the surface of a fused silica wafer by an amplified femtosecond laser system operated in single-pulse mode. Cellulose acetate (CA) film was imprinted into the nanoholes and peeled off to form a patterned array of standing CA nanowires, a negative replica of the laser machined nanoholes. The cellulose acetate replica was then coated with silica in a chemical vapor deposition process using silicon tetrachloride vapor at 65?°C. Field emission scanning electron microscopy, focused ion beam sectioning, energy dispersive x-ray analysis and Fourier-transform infrared spectroscopy were used to characterize the silica nanoneedles. Precisely patterned, functionalized arrays of standing silica nanoneedles are useful for a number of applications.     

车床直线运动误差测试新技术的应用研究

本文阐述用序贯双测头法测量车床直线运动误差的原理,并给出了该方法与其他测试方法(水平仪法、三坐标法、激光干涉法)的对比试验洁果。大量试验结果表明:序贯双测头法的测量精度和测试效率都远远高于其它方法。该方法不仅能测量车床直线运动误差,而且为工件直线度误差在线测量提供了新的测试手段,很有开发应用前景。