Thermopower method for detecting the ferrite-austenite transition: applications to surface reaction and diffusion

Difference of the thermoelectromotive force (temf.) for ferrite and austenite. Measurement of the change of thermopower during the transition ferrite–austenite, as a method for determination of rate parameters and diffusion constants. Application on the carburization and decarburization of Fe and Fe-Ti alloys and on the carbon diffusion in ferrite and austenite.     

Say it Like You Mean it: Priming for Structure in Caller Responses to a Spoken Dialog System

In this paper we report results of a study undertaken to evaluate the initial prompts of open prompt style call-routing applications. Specifically, we examined how placement and phrasing of examples in the initial query affected caller responses and routing success. We looked at the comparative effectiveness of placing examples before and after the initial query and of phrasing these examples such that they promoted either a succinct structure in the form of a keyword or phrase, or a more complex but natural structure in the form of a question or statement. Findings indicate that examples encouraging a more natural structure, when presented prior to the initial query, result in significantly improved routing performance. We discuss this result in the context of using initial prompts to prime for desired structure in caller responses.     

Self-reported and measured time of vibration exposure at ultrasonic scaling in dental hygienists

In the present study, our objective was to quantify the daily duration of vibration exposure from ultrasonic scaling in dental hygienists and to compare different methods of self-estimates to time-recorded measurements. The exposure time was self-estimated by use of diary and interview methods in 10 subjects. We found that the measured total daily exposure time was limited, only on average 12min, with a great variation, however, between and within the subjects. Self-assessed duration of exposure was overestimated, on average three times higher with a diary and even more at an interview (8 times). In conclusion, the objectively measured exposure time was short and clearly overestimated in self-reports.     

Influence of supercritical CO2 on the interactions between maleated polypropylene and alkyl‐ammonium organoclay

Supercritical carbon dioxide (scCO₂) has been proposed as an effective exfoliating agent for the preparation of polymer‐layered silicate nanocomposites, though there is limited fundamental understanding of this mechanism. This study looks at the interactions of this unique green solvent with three maleated polypropylenes of varying anhydride content and molecular size with an alkyl‐ammonium organoclay. Mixtures of compatibilizers and organoclay were melt‐annealed in a high pressure batch vessel at 200°C and subjected to either a blanket of nitrogen or scCO₂ at a pressure of 9.7 MPa. The structures and properties of these melt‐annealed mixtures were characterized by X‐ray diffraction, transmission electron microscopy, Fourier Transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, differential scanning calorimetry, and contact angle measurement. The results indicate that the plasticizing influence of scCO₂ aided intercalation and exfoliation for intercalants of moderate molecular size and anhydride content which would otherwise have limited diffusion into the clay galleries. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Comparison of the UV-Induced Photolysis,Ozonation, and Their Combination at the Same Energy Input Using a Self-Devised Experimental Apparatus

The efficiency of the UV photolysis, ozonation and their combination were compared in the decomposition of phenol using a self-devised experimental apparatus running under identical power conditions. The light source was a low-pressure mercury vapor lamp emitting at 185 nm (responsible for the formation of ozone) and 254 nm (responsible for the direct photolysis of ozone and phenol). The effect of flowrate of oxygen or air on the concentration of formed ozone in the gas phase, the effect of dissolved oxygen and pH on the transformation of phenol and formation of intermediates in aqueous solution were also investigated.     

The Irritant Effects of Pharmaceutically Applied Surfactants

Dermal or transdermal medication may lead to irritant contact dermatitis. However, little information is available on the irritant effect of surfactants which are applied in topical formulations. Our aim was to examine the irritant effect of the most frequent compounds in topical products. A murine model was applied. The following compounds were examined: sodium lauryl sulphate (SLS), polyethoxylated (40EO) hydrogenated castor oil and sucrose laurate. SLS led to severe erythema, increase in transepidermal water loss (TEWL) and induced necrosis and accumulation of neutrophylic granulocytes and lymphocytes. Exposure to sucrose laurate resulted in an elevation of TEWL, but histology did not reveal impairment of the skin structure. Application of polyethoxylated (40EO) hydrogenated castor oil was not accompanied by tissue damage. Special attention should be paid to the irritant effect of SLS. Polyethoxylated (40EO) hydrogenated castor oil seems to be a non-irritant agent and sucrose laurate is also a promising candidate for application in topical preparations.     

Polymeric coatings for photostability enhancement of poly(p‐phenylene vinylene) derivative films

Poly(p‐phenylene vinylene) (PPV) derivatives are an important class of conjugated polymers, known for their applications as electroluminescent materials for light‐emitting devices and sensors. These derivatives are highly susceptible to photodegradation by the combined action of oxygen and light. Here, the use of various commercial polymers as protective coatings against the photodegradation of PPV derivatives was explored. Cast films of two similar PPV derivatives, poly[(2‐methoxy‐5‐n‐hexyloxy)‐p‐phenylene vinylene] and poly[2‐methoxy‐5‐(2‐ethylhexyloxy)‐p‐phenylene vinylene], were submitted to photodegradation by exposure to white light under atmospheric conditions in order to verify if the type of side chain (linear or branched) had an effect on the photodegradation. No significant differences in the photodegradation behaviour between the two polymers were noticed. The following commercial polymers were tested as protective coatings for the PPV derivative cast films: 99 and 80% hydrolysed poly(vinyl alcohol) (PVA) and starch. The best results were achieved using coatings of 99% hydrolysed PVA, which increased about 700 times the time necessary for complete degradation of the PPV derivative films. The results show the effectiveness of this coating in minimizing and, possibly, controlling the effects of the photodegradation of PPV derivative films, which can be useful in many applications, e.g. oxygen sensors. Copyright © 2009 Society of Chemical Industry     

Visualization of Large Experimental Space Using Holographic Mapping and Artificial Neural Networks. Benchmark Analysis of Multicomponent Catalysts for the Water Gas Shift Reaction

This paper reports the combination of Holographic Mapping (HM) and Artificial Neural Networks (ANNs) in order to provide a benchmark visualization of a multi-dimensional space in two-dimensional forms. In this approach each matrix point in HM represents virtual catalytic data generated by means of ANNs in order to visualize the given multi-dimensional experimental space. A 12-dimensional experimental space related to the composition of catalysts designed for the water gas shift reaction (WGSR) from 12 possible components supported on ZrO₂ is visualized. Catalytic data obtained in an earlier combinatorial screening process at 300 °C were used for training of the ANNs. The results show that the visualization of large experimental spaces having more than half a million virtual experimental points can be accomplished. The analysis of synergistic effects between different components revealed that the key components of water gas shift catalysts at 300 °C were Pt, Fe, Eu and V, while Co, Ru, Sb, Ge and Mo had a pronounced negative effect on the activity.     

Hydrogenases, accessory genes and the regulation of [NiFe] hydrogenase biosynthesis in Thiocapsa roseopersicina

The purple (Sulphur) phototrophic bacterium, Thiocapsa roseopersicina BBS contains several [NiFe] hydrogenases, of which two are membrane bound. Mutant T. roseopersicina cells, carrying deletions in both gene clusters showed hydrogenase activity. This activity was located in the cytoplasm. The structural gene cluster hoxEFUYH was identified and sequenced. In addition, genes homologous to hupUV/hoxBC, the hydrogen sensing hydrogenase have been identified and sequenced.Regulation of hydrogenase biosynthesis was studied in detail for HydSL (renamed HynSL). A random mutagenesis system was optimised for T. roseopersicina. One of the mutations was in a gene similar to that coding for the HypF proteins in other organisms. Inactivation of the hypF gene resulted in a 60-fold increase in hydrogen evolution under nitrogen fixing conditions. In addition to hypF, the following accessory genes were identified: hydD, hupK, hypC1, hypC2, hypDE. Characterisation of the corresponding gene products and search for additional accessory genes are in progress.