Active feedback regulation of a Michelson interferometer to achieve zero-background absorption measurements

An active phase-controlling scheme based on a proportional-integral-derivative-controlled piezoelectric transducer is presented with the purpose of stabilizing a quasi-zero-background absorption spectrometer. A fiber-based balanced Michelson interferometer is used, and absorption due to a gas sample in one of its arms results in an increased light signal to a detector, which otherwise, thanks to destructive interference, experiences a very low light level. With the presented approach, the sensitivity of already potent absorption measurement techniques, e.g., based on modulation, could be improved even further.     

An experience sampling study of emotional reactions to music: Listener, music, and situation.

The Experience Sampling Method was used to explore emotions to music as they naturally occurred in everyday life, with a focus on the prevalence of different musical emotions and how such emotions are related to various factors in the listener, the music, and the situation. Thirty-two college students, 20 to 31 years old, carried a palmtop that emitted a sound signal seven times per day at random intervals for 2 weeks. When signaled, participants were required to complete a questionnaire on the palmtop. Results showed that music occurred in 37% of the episodes, and in 64% of the music episodes, the participants reported that the music affected how they felt. Comparisons showed that happiness-elation and nostalgia-longing were more frequent in episodes with musical emotions, whereas anger-irritation, boredom-indifference, and anxiety-fear were more frequent in episodes with nonmusical emotions. The prevalence of specific musical emotions correlated with personality measures and also varied depending on the situation (e.g., current activity, other people present), thus highlighting the need to use representative samples of situations to obtain valid estimates of prevalence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impedance characterization and modeling of electrodes for biomedical applications

A low electrode-electrolyte impedance interface is critical in the design of electrodes for biomedical applications. To design low-impedance interfaces a complete understanding of the physical processes contributing to the impedance is required. In this work a model describing these physical processes is validated and extended to quantify the effect of organic coatings and incubation time. Electrochemical impedance spectroscopy has been used to electrically characterize the interface for various electrode materials: platinum, platinum black, and titanium nitride; and varying electrode sizes: 1 cm2, and 900 microm2. An equivalent circuit model comprising an interface capacitance, shunted by a charge transfer resistance, in series with the solution resistance has been fitted to the experimental results. Theoretical equations have been used to calculate the interface capacitance impedance and the solution resistance, yielding results that correspond well with the fitted parameter values, thereby confirming the validity of the equations. The effect of incubation time, and two organic cell-adhesion promoting coatings, poly-L-lysine and laminin, on the interface impedance has been quantified using the model. This demonstrates the benefits of using this model in developing better understanding of the physical processes occurring at the interface in more complex, biomedically relevant situations.     

Guidelines for Word Alignment Evaluation and Manual Alignment

The purpose of this paper is to provide guidelines for building a word alignment evaluation scheme. The notion of word alignment quality depends on the application: here we review standard scoring metrics for full text alignment and give explanations on how to use them better. We discuss strategies to build a reference corpus, and show that the ratio between ambiguous and unambiguous links in the reference has a great impact on scores measured with these metrics. In particular, automatically computed alignments with higher precision or higher recall can be favoured depending on the value of this ratio. Finally, we suggest a strategy to build a reference corpus particularly adapted to applications where recall plays a significant role, like in machine translation. The manually aligned corpus we built for the Spanish-English European Parliament corpus is also described. This corpus is freely available.     

Accumulation of polybrominated diphenyl ethers, hexabromobenzene, and 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane in earthworm (Eisenia fetida). Effects of soil type and aging

In the present study the accumulation potentials in earthworms (Eisenia fetida) of selected brominated flame retardants (BFRs) were investigated. The tested BFRs, including polybrominated diphenyl ethers (PBDEs), hexabromobenzene (HBB), and 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH), were found to be bioavailable to Eisenia fetida, and they accumulated in the earthworms. To our knowledge, this is the first published study to address the bioaccumulation potential of TBECH in terrestrial biota. Aging the soil resulted in decreased accumulation of TBECH, HBB, and PBDEs with six or less bromine atoms. However, no effect of soil aging was seen for BDEs 183 or 209, possibly due to their low mobility in soil. The use of different soils (artificial OECD soil and two natural Swedish soils) also affected the degree of accumulation in the worms. The results indicate that use of the generally accepted standard OECD soil may overestimate accumulation of organic contaminants by earthworms, due to high bioavailability of the contaminants and/or weight loss of the worms in it. Further, the accumulation of selected PBDEs and HBB was compared to the accumulation of their chlorinated analogues. Brominated compounds accumulated to the same or a lesser extent than their chlorinated counterparts.     

A lithographic approach to determine volume expansion factors during anodization: Using the example of initiation and growth of TiO2-nanotubes

The present work investigates the formation of nanotubes by anodizing titanium at 20 V in glycerol containing either 0.175 M or 0.35 M NH₄F. A photoresist-masking method of thin Ti films allows to use SEM cross-sections to directly obtain information on oxide morphology, layer thickness and metal substrate loss. Therefore not only features of the initial growth stages but also oxide expansion factors can accurately be determined. The expansion factors were found to be 2.4 for the initial formation of a barrier layer, 1.7–1.9 during pore initiation and 2.7–3.1 as the main nanotubes develop. These values (>2.6) suggest substantial contribution to steady state tube growth by a plastic oxide flow mechanism. Combined with RBS efficiency measurements the method presented here allows facile and direct investigation of the mechanism of pore/tube formation.     

Internal doses of acrylamide and glycidamide in mice fed diets with low acrylamide contents

The formation of acrylamide during heating of certain foodstuffs constitutes a potential health hazard. The health risk assessment should be based on knowledge about the relation between dietary exposure to acrylamide and internal doses of acrylamide and its genotoxic metabolite glycidamide. The primary aim of this study in mice was to measure these relationships at low levels of acrylamide intake through the diet. A secondary aim was to clarify which extraction method should be used when analyzing acrylamide in food in order to obtain a correct measure of the acrylamide that is available for absorption. In the analysis procedure, alkaline extraction has earlier shown much higher measured acrylamide levels in certain foods compared to water extraction. In this subcronic study the administered diets were composed to give five levels of acrylamide intakes between 3 and 50 mug/kg body weight per day (calculated on figures obtained after water extraction). Internal doses of acrylamide and glycidamide were measured through hemoglobin (Hb)-adducts. The results showed linear relationships between the exposure of acrylamide and Hb-adduct levels from both acrylamide and glycidamide at these low exposure levels. The study also showed that the "extra" acrylamide measured with alkaline extraction does not correspond to bioavailable acrylamide.     

Proxies and measurement techniques for mineral dust in Antarctic ice cores

To improve quantitative interpretation of ice core aeolian dust records, a systematic methodological comparison was made. This involved methods for water-insoluble particle counting (Coulter counter and laser-sensing particle detector), soluble ion analysis (ion chromatography and continuous flow analysis), elemental analysis (inductively coupled plasma mass spectroscopy at pH 1 and after full acid digestion), and water-insoluble elemental analysis (proton induced X-ray emission). Antarctic ice core samples covering the last deglaciation from the EPICA Dome C (EDC) and the EPICA Dronning Maud Land (EDML) cores were used. All methods correlate very well among each other, but the ratios of glacial age to Holocene concentrations, which are typically a factor approximately 100, differ between the methods by up to a factor of 2 with insoluble particles showing the largest variability. The recovery of ICP-MS measurements depends on the digestion method and is differentfor different elements and during different climatic periods. EDC and EDML samples have similar dust composition, which suggests a common dust source or a common mixture of sources for the two sites. The analyzed samples further reveal a change of dust composition during the last deglaciation.     

Implementation of energy efficiency measures in compressed air systems: barriers,drivers and non-energy benefits

Increased global competition and resource scarcity drives industrial companies to cut costs. Energy can be a significant component of such cuts, particularly for energy-intensive companies. Improving energy efficiency in industry is complex, as it pertains to various energy-using processes that are heavily intertwined. One such process is the compressed air system (CAS), which is used in most industrial companies worldwide. Since energy efficiency improvement measures for various types of energy-using processes differ, technology-specific measures might encounter different barriers to and drivers for energy efficiency. The same applies to the non-energy benefits (NEBs) related to energy efficiency improvement measures; since measures vary between various energy-using processes, the perceived NEBs might be different as well. The aim of this paper is to study the barriers to, drivers for and NEBs of CAS energy efficiency improvement measures from the perspectives of three actors. Carried out as an interview study combined with a questionnaire, the paper merges the perspectives of users, audit experts and suppliers of CASs. The results showed that the major barriers are related to the investment, or are of an organisational character, and that organisational and economic factors seemed to be important for making positive decisions on energy efficiency investments and measures in CASs. Major NEBs for CASs include productivity gains and the avoidance of capital expenditures. The results of this study also address the importance of having a comprehensive approach to recognise additional effects of energy efficiency improvements in CASs.