An investigation of the weld region of the SAE 1020 joined with metal active gas and determination of the mismatch factor

In this study, the joining process of SAE 1020 low carbon steel, generally used in the industry, has been completed using the metal active gas (MAG) weld method. The goal of this study was to examine the mismatch between base and weld metal. After the joining process, mechanical properties of the samples of the base metal (BM), the heat affected zone (HAZ), and the weld metal (WM) were investigated, and the crack tip opening displacement (CTOD) test was performed.     

艾哈迈德·阿德南·萨伊贡艺术中心,伊兹密尔,土耳其

<正>一座建筑的性能应当如何来衡量?除了通过统治当代建筑舆论的美学、技术以及经济价值来进行描述之外,我们还能够如何来阐释一座建筑,尤其是一座致力于庇护那些渴望展现自己的艺术家的建筑?有人会问成功的表演是如何实现的,表演者是如何进行伪装的、又是如何展现自己的?根据海德格尔的理论,当我们看不到钉子的时候,铁锤的表现才是成功的;钉子本身的出现通常表明出现了问题。     

Micelle-hosted bimetallic Pd–Ru nanoparticle for in situ catalytic hydrogenation in supercritical CO2

Bimetallic Pd–Ru nanoparticles of different elemental ratios are prepared via in situ reduction of their simple salts in reverse micelles in supercritical carbon dioxide (scCO₂). The optimised Pd:Ru (1:1) nanoparticle shows the highest activity for hydrogenation of functionalised alkene under mild conditions, which can be easily recycled under the reaction conditions without use of organic solvent.     

Optimal loading of solids by the boundary element method

Optimal boundary loading of solids in elastostatics is analyzed within the framework of optimal control problems. First, the necessary conditions of optimality are found by means of calculus of variations. The resulting sets of vector PDE's are then discretized in space by using the boundary element method, while an integral function (the performance index of the control problem) is minimized by the conjugate gradient method of optimization. Numerical results are provided for a thin plate of annular sector.     

Psychopathological profile of tinnitus sufferers: evidence concerning the relationship between tinnitus features and impact on life

This study involving 281 French tinnitus sufferers sought to investigate possible correlations between psychopathological profile and scores obtained from three tinnitus questionnaires. The patients all completed a French version of the Mini-Mult--a shortened Minnesota Multiphasic Personality Inventory--and French translations of three questionnaires designed especially for the clinical assessment of tinnitus: Tinnitus Reaction Questionnaire (TRQ), Subjective Tinnitus Severity Scale (STSS) and Tinnitus Handicap Questionnaire (THQ). Significant correlations were found (p < 0.0001) between scores on various Mini-Mult scales and total or factor 1 THQ and total TRQ scores. No significant correlation was found between the STSS and any Mini-Mult score.     

Shape design sensitivity analysis for non-linear anisotropic heat conducting solids and shape optimization by the BEM

Shape design sensitivity analysis (SDSA) expressions have been derived for non-linear anisotropic heat conducting solid bodies by following the material derivative concept and adjoint variable method of optimal shape design given in the literature. The variation of a general integral functional has been described in terms of primary and adjoint quantities evaluated at the varying boundaries. As an example problem in shape optimization, optimal outer boundary profiles of an orthotropic solid body are obtained by the boundary element method (BEM), after reformulating the SDSA equations in a form which is most suitable for the BEM.     

Heterogenous photocatalytic degradation kinetics and detoxification of an urban wastewater treatment plant effluent contaminated with pharmaceuticals

Degradation kinetics and mineralization of an urban wastewater treatment plant effluent contaminated with a mixture of pharmaceutical compounds composed of amoxicillin (10 mg L⁻¹), carbamazepine (5 mg L⁻¹) and diclofenac (2.5 mg L⁻¹) by TiO₂ photocatalysis were investigated. The photocatalytic effect was investigated using both spiked distilled water and actual wastewater solutions. The process efficiency was evaluated through UV absorbance and TOC measurements. A set of bioassays (Daphnia magna, Pseudokirchneriella subcapitata and Lepidium sativum) was performed to evaluate the potential toxicity of the oxidation intermediates. A pseudo-first order kinetic model was found to fit well the experimental data. The mineralization rate (TOC) of the wastewater contaminated with the pharmaceuticals was found to be really slow (t_1/2 = 86.6 min) compared to that of the same pharmaceuticals spiked in distilled water (t_1/2 = 46.5 min). The results from the toxicity tests of single pharmaceuticals, their mixture and the wastewater matrix spiked with the pharmaceuticals displayed a general accordance between the responses of the freshwater aquatic species (P. subscapitata > D. magna). In general the photocatalytic treatment did not completely reduce the toxicity under the investigated conditions (maximum catalyst loading and irradiation time 0.8 g TiO₂ L⁻¹ and 120 min respectively).     

On the gravity flow of granular materials

The governing equations for flow of an incompressible and cohesionless material are solved approximately by a new procedure. In this procedure the equilibrium equations and the yield criterion are satisfied identically through invocation of the Airy stress function and the Sokolovski functions. The problem analysed pertains to radial flow in a wedge-shaped hopper for which some experimental results are available. The computed results exhibit qualitative features which are similar to those obtained by other investigators using different solution procedures. Quantitatively however the present results are in better agreement with experimental results, than theoretical results obtained hitherto subject to similar assumptions.     

Determination of microwave drying and rehydration kinetics of green peppers with the bioactive and textural properties

The aim of this study was to determine the effect of microwaves on drying and rehydration kinetics of green pepper varieties (sweet, green, and bell) and the bioactive and textural properties of dried and rehydrated peppers. Drying was performed at 90, 180, and 90 + 180 W and dried peppers were rehydrated at 25, 50, and 70°C. The best drying fits were obtained using the equations of both Sigmoid and Hii et al. for drying, and two term exponential decay was the most appropriate model for rehydration. The lowest and highest final rehydration ratio values were obtained for the peppers dried at 180 and 90 W, respectively at each temperature and pepper variety. Among peppers, bell pepper showed the lowest color change (ΔE) and it was the most potent to recover initial color in rehydration. Peppers had softer texture in both drying and rehydration treatment. Total phenolic content of peppers was reduced around 56–65% compared to the fresh pepper by drying and this decrement was reached up to 87% in rehydrated peppers. Results showed that drying at 180 W and rehydration at 70°C provided faster drying and rehydration as well maintained the quality characteristics of green peppers.