Influence of stress-strain field on the dissolution process of polycrystalline nickel in H2SO4 solution: An original in situ method

Stress corrosion cracking (SCC) raises a lot of questions concerning complexity of stacked physical mechanisms. Synergy between electrochemical processes and mechanical field near the crack tip is now recognized. However, the influence of mechanical behaviour on corrosion processes is not well established and only few works dealt with this effect. Consequently, it seems to be necessary to determine the influence of the plastic strain on the surfaces reactivity in aqueous mediums. The great part of this work was devoted to the development of an electrochemical cell on a bench of mechanical test in order to carry out in situ measurements of current density. Three levels of interaction have been discussed taking into account the different expression of plastic deformation (dislocation density and distribution, slip bands emergence, stress field) in order to study the effect of mechanical state on dissolution, on passivation processes, and on stability of oxide film of polycrystalline nickel in H₂SO₄ solution.     

New proposal of reactivity coefficient estimation method using a gray-box model in nuclear power plants

A new method for estimating reactivity parameters, such as moderator temperature coefficient (MTC) and void reactivity coefficient (VRC), is proposed using steady-state noise data. In order to solve the ill-posed problem of reactivity parameter estimation, a concept of a gray box model is newly introduced. The gray box model includes a first principle based model and a black-box fitting model. The former model acts as a priori knowledge based constraints in a parameter estimation problem. After establishing the gray box and noise source models, the maximum likelihood estimation method based on Kalman filter is applied. Furthermore, it is shown that the frequency domain approach of the gray box model is useful in the case of VRC estimation. The effectiveness of the proposed algorithms is shown through numerical simulation and actual plant data analysis.     

Does completing a craving questionnaire promote increased smoking craving? An experimental investigation.

The authors evaluated whether completing a multi-item assessment of smoking craving (the Questionnaire of Smoking Urges [QSU]) promoted increases in smoking craving. A sample of 39 regular smokers was randomly assigned to 1 of 3 manipulations (each of 3 min duration): (a) complete the QSU–Brief (10 items), (b) complete a noncraving questionnaire that was structurally identical to the QSU–Brief (scale-based control), and (c) a time-based control. Participants responded to an oral question assessing their degree of craving immediately before and after the manipulations. Results indicated that the QSU did not promote increases in craving compared to the 2 control conditions. Despite continuing debate over the most appropriate self-report measure of craving, investigators who use the QSU–Brief can be reasonably sure that the scores that result are not biased due to reactivity effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Duchenne smile, emotional experience, and autonomic reactivity: A test of the facial feedback hypothesis.

This study examined the modulatory function of Duchenne and non-Duchenne smiles on subjective and autonomic components of emotion. Participants were asked to hold a pencil in their mouth to either facilitate or inhibit smiles and were not instructed to contract specific muscles. Five conditions--namely lips pressing, low-level non-Duchenne smiling, high-level non-Duchenne smiling, Ducherme smiling, and control--were produced while participants watched videoclips that were evocative of positive or negative affect. Participants who displayed Duchenne smiles reported more positive experience when pleasant scenes and humorous cartoons were presented. Furthermore, they tended to exhibit different patterns of autonomic arousal when viewing positive scenes. These results support the facial feedback hypothesis and suggest that facial feedback has more powerful effects when facial configurations represent valid analogs of basic emotional expressions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thermochemical Conversion of Sewage Sludge by TGA-FTIR Analysis: Influence of Mineral Matter Added

Thermal treatments, such as combustion, gasification, and pyrolysis, have been proven to be a convenient alternative to conventional sludge disposal technologies. Today, process development implies scaling up and so improving the reactor's design. In continuously operated reactors, fresh sewage sludge is in contact with solid residues (reacted material rich in mineral matter and char). Mineral matter has been reported to catalyze the thermo-chemical reactions involved but few works focus on this aspect. In this work, sewage sludge residues were added to fresh sewage sludge. Non-isothermal thermo-gravimetric analysis (TGA) coupled with infrared spectrometry (FTIR) showed that added residues reduce the characteristic reaction temperatures during char combustion and gasification (air, air-N₂, and CO₂ atmospheres). However, any considerable influence of residues was observed during pyrolysis experiments (N₂ atmosphere). The analysis of gas produced during those experiments revealed further details about the solid decomposition, showing considerable differences between different atmospheres.     

低温固化聚酯卷材涂料的研制

选用合适单体合成高反应活性聚酯树脂,介绍了树脂的合成工艺,以高亚氨基部分醚化氨基树脂为交联剂,自制二壬基二磺酸为催化剂,制成低温固化卷材涂料。所制备的涂料具有很好的耐候性和加工成型性能。讨论了影响涂料性能的因素。     

Experimental study on CO2 capture conditions of a fluidized bed limestone decomposition reactor

In this study, the decomposition conditions of limestone particles (0.25-0.50 mm) for CO₂ capture in a steam dilution atmosphere (20-100% steam in CO₂) were investigated by using a continuously operating fluidized bed reactor. The results show that the decomposition conversion of limestone increased with the steam dilution percentage in the CO₂ supply gas. At a bed temperature of 920 °C, the conversions were 72% without steam dilution and 98% with 60% steam dilution. The conversion was 99% with 100% steam dilution at 850 °C of the bed temperature. Steam dilution can decrease not only the decomposition temperature of limestone, but also the residence time required for nearly complete decomposition of CaCO₃. The hydration and carbonation reactivities of the CaO produced were also tested and the results show that both the reactivities increased with the steam dilution percentage for decomposing limestone.     

钙基CO_2吸收剂循环活性衰减原因初探

对钙基CO2吸收剂的循环活性衰减进行了实验研究,考察了随着循环次数的增加,吸收剂的表面形态、吸收剂分子孔径及比表面积等微观结构的变化,分析了钙基CO2吸收剂循环活性衰减的原因。结果表明,随着循环次数的增加,吸收剂晶粒中的片状结构已经完全消失,取而代之的是正方体状的大晶粒,晶粒生长严重,大量空隙被封闭。而由此引起的吸收剂的比表面积的不断减小和孔容积的降低以及孔分布的改变,导致了吸收剂循环活性的衰减,吸收剂的循环转化率降低。     

粉煤灰与炉底渣的蒸压反应活性研究

粉煤灰和炉底渣均为燃煤发电过程中产生的固体废弃物,但两者的反应活性有所区别。研究结果表明,炉底渣的玻璃相含量以及活性SiO2、Al2O3含量均高于粉煤灰,在蒸压条件下炉底渣的反应活性优于粉煤灰,有利于生成更多的水化产物。利用炉底渣部分或全部取代粉煤灰制备蒸压硅酸盐制品,有利于提高制品的强度。     

Wetting and interfacial reactions in liquid Au-Ti alloys / ZrO2 system

This study investigates wetting of zirconia by Au-Ti alloys containing 0.6–4 wt% Ti in view of brazing zirconia to titanium with pure gold for biomedical applications. Experiments were carried out using sessile and dispensed drop methods under high vacuum at 1040–1250 °C. Bulk drops and Au-Ti / ZrO₂ interfaces were characterized by SEM and FEG-SEM with EDXS analysis. While Au does not wet zirconia, the contact angle θ being ∼ 120°, the addition of Ti in Au leads to a significant improvement of wetting due to the formation of a wettable oxide layer at Au-Ti / ZrO₂ interface. The nature of this oxide was determined by X-ray diffraction of the reaction layer after the detachment of the droplet from the substrate or after the dissolution of the droplet. The mechanism of formation and growth of the oxide layer and its growth kinetics were determined based on fine analysis of the Au-Ti / oxide layer / ZrO₂ interfacial system.