Reaction kinetics of metal deposition via surface limited red-ox replacement of underpotentially deposited metal monolayers

The study of the kinetics of metal deposition via surface limited red-ox replacement of underpotentially deposited metal monolayers is presented. The model system was Pt submonolayer deposition on Au(1 1 1) via red-ox replacement of Pb and Cu UPD monolayers on Au(1 1 1). The kinetics of a single replacement reaction was studied using the formalism of the comprehensive analytical model developed to fit the open circuit potential transients from deposition experiments. The practical reaction kinetics parameters like reaction half life, reaction order and reaction rate constant are determined and discussed with their relevance to design and control of deposition experiments. The effects of transport limitation and the role of the anions/electrolyte on deposition kinetics are investigated and their significance to design of effective deposition process is discussed.     

Thermodynamic properties of S-Fe-Co-Ni and Fe-Co-Ni systems

The values of sulfur activity in the liquid S-Fe-Co-Ni system were determined from unpublished equilibrium data for H₂ +S (in alloy) = H₂S. The activity coefficient of sulfur varied from 0.387 to 1.896 and increased with increasing concentrations of Fe and Co. The published values for the activities in the binary systems Fe-Co, Fe-Ni, and Co-Ni were used to calculate the activities in the ternary Fe-Co-Ni alloys, and these results were expressed as a function of composition. This function was used with the activity coefficients of S in the binary metal solvents to express the activity coefficient of S in the ternary metal solvents as a function of mol fractions of Fe, Co, and Ni. The experimental values for S in Fe-Co-Ni agreed well with the calculated values based on the binary metal solvents, and this showed that all the activity values were consistent.     

Glycation of soy protein isolate with two ketoses: d-Allulose and fructose

Modification of food proteins to have improved functional properties is of great importance. In this study, modification of soy protein isolate (SPI) was achieved through glycation. SPI was glycated in a spray dryer (SD) and an incubator followed by freeze drying (FD). d -Allulose, an important rare sugar, was used in SPI glycation as the carbohydrate source, and results were compared with fructose. In addition to the sugar type, two different SPI powder: sugar ratios (1:1 and 5:1) were investigated. For the glycated samples, emulsification activity, free amino groups, protein solubility, Fourier-transform infrared spectroscopy analysis, antioxidant activity experiments and time-domain NMR relaxometry measurements for hydration were conducted. According to the results, the solubility of SPI that is limited in native form has shown a significant improvement after glycation through both FD and SD methods. Besides, glycation through the FD method was found to be more favourable due to its milder conditions than the SD method. Considering the physicochemical properties, the best combination for the highest glycation degree was found to be the samples prepared at the 1:1 ratio with d -Allulose in the FD method. Overall, it was concluded that glycation of SPI enhanced its functional properties such as antioxidant and emulsification activities.     

The As-Sn (Arsenic-Tin) system

This work was partly supported by ASM INTERNATIONAL. Dr. Gokcen is the ASM/NIST Data Program Category Editor for binary manganese, lead, and silicon alloys.     

Nitrogen concentration in liquid Fe-Mn alloys at high pressure

The U.S. Bureau of Mines has been studying the effects of increasing the N concentration in Fe alloys as an effective technique for increasing mechanical properties and improving corrosion resistance. N concentration in liquid Fe- Mn alloys was determined as a function of N pressure (1 to 2000 bars) and Mn concentration (0 to 30 wt.%). Samples were melted in a hot- isostatic- pressure furnace using N as the pressurizing gas. Measured N concentration in the solidified alloys was determined to be the same as that in the melt. Deviations from Sieverts’ law were observed at higher pressures and Mn concentrations. Correlation techniques that account for the effects of pressure on the N concentration. Nitrogen high-pressure melts were conducted at the U.S. Bureau of Mines, Tuscaloosa Research Center, Alabama.     

Gas chromatography-isotope dilution mass spectrometry method validation for target pesticides in soybeans

The production of certified reference materials requires the application of highly accurate methods for characterisation. A gas chromatography-isotope dilution mass spectrometry method, setting ambitious performance criteria, was developed for eight selected pesticides in soybeans. Pressurised liquid extraction was followed by automated gel-permeation chromatography and solid-phase extraction clean-up. Pesticides identification respected a Commission Decision and guidelines of the Directorate General for Health and Food Safety (DG SANTE). Reliable quantification involved stable isotopically labelled analogues as internal standards. Validation, according to ISO/IEC 17,025 and DG SANTE guidelines, assessed linearity, LOD/LOQ, trueness, selectivity, precision, stability and robustness. Mean recoveries ranges (83–109%, relative standard deviations < 3%), repeatability (2.2–4.8%), day-to-day variation (0.6–4.2%) and combined uncertainty (1.2–4.2%) were fit for purpose. The method is highly accurate and suitable for certification of the selected pesticides in soybean matrix reference material.

Chemical compounds studied in this article: Diazinon (PubChem CID: 3017); malathion (PubChem CID: 4004); chlorpyrifos (PubChem CID: 2730); captan (PubChem CID: 8606); endosulfan (PubChem CID: 3224); tebuconazole (PubChem CID: 86,102); iprodione (PubChem CID: 37,517); cypermethrin (PubChem CID: 2912).     

Determination and analysis of site selection factors for kulliyes of architect Sinan with respect to the locations in the Ottoman city of Istanbul

Besides serving with their public and religious functions to the city, Ottoman kulliyes were the focal points which develop the urban pattern of their surroundings and the city. Sinan's kulliyes were established as important centers both serving the society and expressing the imperial power during the busiest years of the empire in terms of construction and building activities. Their location in the city was chosen particularly and many parameters were taken into account and evaluated while deciding upon the site selection. On the other hand, the fact that each kulliye might have its own specific conditions makes it difficult to determine the parameters in question. Generalizing to some extent, this study aims to determine the site selection factors and puts the effects of these factors forward in both site selection and space arrangements of the kulliyes all of which stand on different points of the city. Within the framework of the aim of the study, the analysis and its findings provide not only to determine how the kulliyes were located in the city but also indicate the importance of site selection and its effects on the built environment in architecture by means of Sinan's kulliyes. Identification of these effects would also demonstrate whether there is an interaction between site selection and formation of the kulliyes. The presence of the interaction in other words formation of the complex with respect to its location would be an indicator of the relationship of buildings with its surroundings and even with the city.