Near-infrared spectroscopy investigation on the hydration degree of a cement paste

Near-infrared spectroscopy is a fast and easy-to-perform technique characterized by high sensitivity regarding water containing systems and for this reason it is a suitable tool for investigating structural modifications of hydrating cementing materials, even if the lack of knowledge in this field makes the interpretation of NIR vibrational bands very difficult. In this paper, the NIR spectrum of a hydrated ordinary Portland cement is extensively investigated and an interpretation of the different bands is proposed on the basis of both experimental evidence and reference to literature. The obtained results were applied to the investigation of cement hydration lasting up to 28 days, analyzing the variations detectable in the shape of the spectrum as the reaction went on. The degree of this variation, quantified through area calculations of the main significant bands, revealed a broad agreement with the degree of hydration of the paste measured by thermal methods. The findings of this research supply a solid foundation for future in-field application of NIR spectroscopy, for example, for investigations on cements with different hydration behavior, or to evaluate the effect of additives on cement pastes and, at a further level, for cement quality control.     

Fast‐squarer circuits using 3‐bit‐scan without overlapping bits

This paper presents a novel technique to design fast‐squaring circuits. The proposed approach speeds up squaring operations combining the 3‐bit scan without overlapping bits and the folding technique. Several hardware implementations of squarer circuits designed as described here are characterized for several operand wordlengths. Obtained results demonstrate that, using the ST 90 nm 1V CMOS technology, a 32‐bit squarer exploiting the novel way of generating partial products reaches a 769 MHz running frequency, dissipates less than 19.3 mW on average and occupies ～91 000µm² of silicon area. Copyright © 2010 John Wiley & Sons, Ltd.     

Highly Sensitive Sensors for the Detection of Nitro Compounds Based on Pyrene Labeled Dendrons

In this paper, we describe the synthesis and characterization of four novel pyrene labeled compounds, some of them dendritic, which can act as potential sensors for the detection of nitro compounds in methanol solution. Methanol was selected as solvent due to its polar properties, which provide similar characteristics to water. The obtained pyrene labeled molecules (PyOH, Pytb, PyNK1OH and PyNK1tb) were studied by UV–Vis and steady state fluorescence spectroscopy. Their application as sensors has been tested with three different nitro compounds: nitrobenzene, 1-chloro-2,4-dinitrobenzene and nitromethane. PyOH and Pytb showed a detection concentration limit for the analyzed quenchers in the order of nM, making these compounds suitable for high-sensitive sensoring. PyNK1OH and PyNK1tb displayed high sensibility at µM concentration. All the sensors showed an accurate response towards quencher analytes.     

Strain sensing fabric for hand posture and gesture monitoring.

In this paper, we report on a new technology used to implement strain sensors to be integrated in usual garments. A particular conductive mixture based on commercial products is realized and directly spread over a piece of fabric, which shows, after the treatment, piezoresistive properties, i.e., a change in resistance when it is strained. This property is exploited to realize sensorized garments such as gloves, leotards, and seat covers capable of reconstructing and monitoring body shape, posture, and gesture. In general, this technology is a good candidate for adherent wearable systems with excellent mechanical coupling with body surface. Here, we mainly focused on a sensorized glove able to detect posture and movements of the fingers. It could be used in several fields of application. We report on experimental results of a sensorized glove used as movements recorder for rehabilitation therapies and medicine. Furthermore, we describe a dedicated methodology used to read the output sensors which allowed to avoid using metallic wires for the connections. The price to be paid for all these advantages is a nonlinear electric response of the fabric sensor and a too long settling time, that in principle, make these sensors not suitable for real-time applications. Here we propose a hardware and computational solution to overcome this limitation.     

Pyrolysis of glass-hardened polyamides used in the automotive industry

Thermogravimetry and on-line flash pyrolysis–gas chromatography–mass spectrometry were used for studying thermal decomposition processes in filled polyamides deriving from used cars. The thermal decomposition of each polymer begins at about 350 °C and proceeds with a weight loss of 100% for the non-glass fibres, under nitrogen atmosphere. The analysis of the pyrolyzate compounds shows that from polyamide 66, the most abundant product volatile at degradation temperatures is cyclopentanone, while from polyamide 6 there is a considerable yield of ε-caprolactam. This revised version was published online in November 2006 with corrections to the Cover Date.     

Effect of different ventilation regimens on ewes' milk and Canestrato Pugliese cheese quality in summer

The influence of three different ventilation regimens on air pollution in sheep houses and on the quality of ewe milk and of Canestrato Pugliese cheese was investigated during the summer season. The experimental treatments were low ventilation regimen (VR=35 m3/h per ewe) split in 30-min ventilation cycles (LOV-30); moderate ventilation regimen (VR=70 m3/h per ewe) split in 30-min ventilation cycles (MOV-30); moderate ventilation regimen (VR=70 m3/h per ewe) split in 60-min ventilation cycles (MOV-60). The LOV-30 milk had higher microbial load and bulk milk somatic cell count (BMSCC) and resulted in a weaker casein matrix in the curd compared with the MOV-30 and MOV-60 treatments. At 45 d of ripening, the LOV-30 cheeses had a lower casein content and higher non-casein nitrogen (NCN) and water-soluble nitrogen (WSN) contents than the MOV-30 and MOV-60 cheeses. Urea-polyacrylamide gel electrophoresis (urea-PAGE) of the pH 4.6-soluble N extract showed that the MOV-60 cheeses had fewer bands derived from casein (CN) hydrolysis than the LOV-30 or MOV-30 cheeses, despite its having exhibited the highest plasmin (PL) activity levels. Our results suggest that the ventilation regimen is critical in dairy sheep housing for optimizing the hygienic quality of ewe milk and the proteolytic processes occurring in Canestrato Pugliese cheese during ripening.     

Analysis of Residual Stresses and Dislocation Density of AA6082 Butt Welds Produced by Friction Sir Welding

Metallurgical and Materials Transactions A - The Friction Stir Welding (FSW) method was employed to join AA6082 sheets. The welds were produced with different tool traverse speed (200 and...     

Optimal multicast routing with quality of service constraints

We consider the problem of optimal multicast routing with Quality of Service constraints motivated by the requirements of interactive continuous media communication, e.g., real-time teleconferencing. We concentrate on distributed algorithms for determining a tree over the network topology, rooted at the source and spanning the intended destinations. Quality of Service requirements for interactive continuous media typically impose constraints on some metric over the individual paths from the source to each destination, usually in the form of an upper bound on the delay. Thus, we focus on the problem of minimizing the cost of the tree while at the same time satisfying a common constraint over individual source-destination paths. We have shown that this problem is intractable, but have also devised centralized polynomial time heuristics that perform well. Here we present distributed algorithms to minimize tree cost while satisfying the constraints on the paths from the source to each destination.     

L'accessibilité à des traitements pour les troubles anxieux au Canada: Un commentaire.

Responds to Gauthier (see record 2004-17185-003) who commented on the two articles by Koerner et al (see record 2004-17185-001) and by Roberge et al (see record 2004-17185-002. The purpose of this response is to discuss the issue of limited availability of mental health services for anxiety disorders in Canada. From a public health perspective, the authors emphasize the importance of gathering Canadian empirical data on the organization of mental health services for anxiety disorders. Specifically more research is needed on care requirements, and the financial and structural barriers that restrict access to mental health services at the regional, provincial and national levels. The authors also discuss the role of psychologists in improving mental health care in Canada. Cost-effectiveness studies conducted in interdisciplinary practice environments could demonstrate the value added by psychology in the organization of mental health care for anxiety disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)