The effect of par‐baking and frozen storage time on the quality of cup cake

The effects of frozen storage and initial baking time of par‐baked cake on baking loss, volume, moisture, colour and textural properties of cake obtained after thawing and rebaking were investigated. Cakes, par‐baked at 175 °C for 15, 20 and 25 min, were stored at ?18 °C for 3, 6 and 9 months. After storage, par‐baked cakes were thawed and rebaked at 175 °C for 10, 15 and 20 min. Baking loss, moisture content, L and +b colour values, firmness, gumminess and chewiness of the resulting full‐baked cakes were significantly affected by both par‐baking and frozen storage time, while specific volume, cohesiveness, springiness and resilience values were significantly affected by frozen storage time. The increase in the time of frozen storage of the par‐baked cake leads to a decrease in the quality of the rebaked cake, namely an increase of baking loss and cake crumb firmness, and a loss in the moisture content and specific volume. Moisture of cake crumb, L and +b colour values, firmness, gumminess and chewiness significantly increased as the par‐baking time increased. However, regarding baking loss, specific volume, moisture content and textural properties, 3‐month intermediate storage at ?18 °C and 20‐min initial baking time gave the best result among the cakes produced by using the two‐step baking procedure.     

Diagnostic methods of primary tuberculous pleural effusion in a region with high prevalence of tuberculosis. A study in Mexican population

STUDY OBJECTIVES: 1) To determine the age distribution of the patients with pleural tuberculosis in a region with high prevalence of tuberculosis; and 2) to evaluate the efficiency of the methods used in its diagnosis. SETTING: The National Institute of Respiratory Diseases in Mexico City, a tertiary reference center for pulmonary diseases. DESIGN: A retrospective study. PATIENTS: 452 consecutive inpatients with diagnosis of pleural effusion from January 1991 to September 1996 were reviewed: 133 patients had a diagnosis of tuberculous pleural effusion of primary origin without parenchymal abnormalities by chest roetgenogram. The others were excluded because of reactivated tuberculosis or non-tuberculous effusion. MEASUREMENTS AND RESULTS: The patients had a mean age of 42 +/- 17 years (98 male, 35 female). Pleural granulomas in the morphological study were found in 87% whereas the baciloscopy and the culture of the fluid were positive in only 8% and 19% respectively. The determination of adenosine deaminase (ADA) gave a diagnostic yield of 84%. CONCLUSIONS: 1) Primary tuberculosis pleural effusion, reported in the English literature, was also present in our adults; 2) the pleural biopsy continued to be the most effective method in the diagnosis of the pathology; and 3) the determination of ADA in an area with high prevalence of the disease was a reliable and unexpensive diagnostic method.     

激光重熔工艺参数对热障涂层热震性能的影响

在GH536高温合金基材上等离子喷涂氧化钇部分稳定氧化锆(8YSZ)热障涂层后,采用连续CO2激光进行表面陶瓷层激光重熔,得到了表面形貌、组织结构符合质量要求的涂层。热震试验结果表明,在本试验的失效判据下,等离子喷涂及激光重熔试样的失效形式和机理不同,等离子喷涂试样为热震应力失效,激光重熔试样以热震应力和TGO应力共同作用形式失效。激光能量密度为4.0J/mm2时,激光重熔试样具有略高于等离子喷涂试样的热震寿命,当激光能量密度较高时,激光能量分布不均导致的组织及结构的不均匀,柱状晶粗化是能量密度较高的表征,扩展到喷涂态陶瓷层中的裂纹是激光重熔试样热震寿命降低的主要原因。     

A New Application of Solvent Extraction to Separate Copper from Extreme Acid Mine Drainage Producing Solutions for Electrochemical and Biological Recovery Processes

Over the last decade, AMD waters have gained more attention as a potential source of metals due to the emerging need to recover or recycle metals from secondary resources. Metals recovery supports sustainability and the development of a circular economy with benefits for resource conservation and the environment. In this study, five extractants (Acorga M5640, LIX 54, LIX 622, LIX 622 N, and LIX 864) diluted (15% (v/v)) in Shell GTL with 2.5% (v/v) octanol were compared and evaluated for Cu recovery from an extreme AMD sample (5.3?±?0.3 g/L Cu) collected at the inactive São Domingos Mine in the Iberian Pyrite Belt of Portugal. Of the five extractants, Acorga M5640 showed the best selective efficiency. Further tests showed that 30% (v/v) of this extractant was able to selectively extract ≈ 96.0% of the Cu from the AMD in one extraction step and all of the remaining Cu (to below detection) in three steps. Among the different stripping agents tested, 2 M sulfuric acid was the most efficient, with ≈ 99% of the Cu stripped, and the recyclability of the organic phase was confirmed in five successive cycles of extraction and stripping. Furthermore, contact time tests revealed that the extraction kinetics allows the transfer of ≈ 97% of the Cu in 15 min, and aqueous to organic phase ratios tests demonstrated a maximum loading capacity of ≈ 16 g/L Cu in the organic phase. Raising the concentration of Cu in the stripping solution (2 M sulfuric acid) to ≈ 46 g/L through successive striping steps showed the potential to recover elemental Cu using traditional electrowinning. Finally, a biological approach for Cu recovery from the stripping solution was evaluated by adding the supernatant of a sulfate-reducing bacteria culture to make different molar ratios of biogenic sulfide to copper; ratios over 1.75 resulted in precipitation of more than 95% of the Cu as covellite nanoparticles.

Graphical Abstract

     

Rubber effect on metallic dampers used on the supports of steel cross members

There are many strengthening methods made with steel cross members for strengthening the structures with inadequate earthquake behavior. This type of strengthening methods is also effective in buckling of the cross members in the behavior of the structural frames. This buckling may cause partial or complete collapse of the structure. Thus, it is quite important to prevent and limit the formation of buckling in steel crosses. At the TEC 2018, the insulation unit is defined as the elements that can exhibit flexible behavior on the horizontal direction and rigid behavior on the vertical direction under the effect of earthquake loads. The basic principle of using insulation units is that these members can dissipate energy in the carrier system. The originality of this study is to experimentally investigate the damper behavior created by using cylindrical rubber wedges, which can be easily found in the automotive industry, in combination with steel plates and bolts. In this experimental study, the contribution of seismic insulators to the structural element to be strengthened was investigated. The insulators used in this study are considered by analogy with lead-core rubber insulators. As such seismic lead-core rubber insulators move under the influence of lateral loads, the lead core inside makes plastic deformation, thus increasing the damping rate. In this insulator study, it is aimed to use U plates or bolts instead of lead core. While vertical loads are covered by rubber support, horizontal loads will be damped due to plastic deformation of U plates or bolts. The five types of seismic dampers were used as 10 B-type rubber wedge mounted damper (SR), 2 U-type steel plates damper (SP), 10 M6 steel bolted damper (SB), 2 U-type steel plates and 10 B-type rubber wedge mounted damper (SPR), 10 M6 steel bolted, and 10 C-type rubber wedge mounted damper (SBR). These specimens were tested under lateral loading and constant vertical loading. The results obtained at the end of the tests shall be compared considering the strength, stiffness, and dissipated energy capacities of the specimens.     

变压吸附法回收氢气

介绍了变压吸附法回收氢气的原理、工艺流程、运行方式等,并分析了运行效果和经济效益。     

Amphiphilic Properties of Dodecylammonium Chloride/4-(1-Pentylheptyl) Benzene Sodium Sulfonate Aqueous Mixtures and Study of the Catanionic Complex

Surfactants are often used in supramolecular chemistry, due to their ability to self-organize. Surfactant molecules aggregate spontaneously and reversibly to adopt a defined intermolecular arrangement. In this work, general phase behavior, adsorption and association in aqueous mixtures of dodecylammonium chloride, DACl and sodium 4-(1-pentylheptyl) benzenesulfonate, NaDBS, were studied by a combination of techniques including surface tension and conductivity measurements, light scattering and optical microscopy. The strong synergistic properties of the system were brought out with the Regular Solution Theory. Various colloidal objects are observed in wide range of composition: conventional small vesicles, large giant multilamellar or multivesicular vesicles. An excess of NaDBS provides extremely large tubular and elongated multilamellar vesicles. The new catanionic 1:1 complex, dodecylammonium-4-(1-pentylheptyl) benzenesulfonate, formed in the equimolar conditions is a result of intramolecular charge neutralization. The thermal properties of this solid compound were examined by thermal polarizing microscopy, differential scanning calorimetry, and X-ray diffraction. The most probable ion-pair amphiphilic cluster of the crystal smectic phase, at room temperature, consists of ionic groups formed in ordered layers with dodecyl chains packed into somewhat disordered layers, tilted to the layer plane.     

Ionic liquid intercalated clay nanofillers for chromatographic applications

In this study, the preparation and characterization of ionic liquid (IL) intercalated montmorillonite (MMT) and their application as a micro-solid phase extraction material for the determination of Chlorpyrifos (CP) pesticide in water samples were reported. The ionic liquids bearing different chain lengths [1-methyl-3-octylimidazolium bromide (C₈mimBr), 1-methyl-3-undecyl-imidazolium bromide (C₁₂mimBr) and 1-methyl-3-octadecyl-imidazolium bromide (C₁₈mimBr)] were intercalated in the galleries of MMT. The IL-intercalated MMTs were characterized by means of XRD and TG methods. The (C₁₂mimBr)-intercalated MMT had the highest sorption efficiency for the CP, which was 32 times higher than the original MMT. We also optimized the parameters for extracting CP from the (C₁₂mimBr)-intercalated MMT.