Measurement of calcium ion suppression by protection of foam of sodium cetyl sulfate solutions

Summary Relative protection of various compounds against calcium salts was determined by a pour-foam test, using sodium cetyl sulfate as a foam-producing indicator. The sensitivity of the test corresponds to less than 2 p.p.m. of calcium salt. Some of the data are compared with similar tests, using sodium oleate as an indicator, and advantages of the cetyl sulfate test are noted. The test is discussed from the point of view of a competition for calcium ion by the cetyl sulfate anion to precipitate calcium cetyl sulfate and by the compound tested to precipitate a calcium salt or form complex calcium ions. On the basis of the equilibria involved an estimate is made of the approximate solubility of calcium cetyl sulfate in the salt solutions tested.     

Characterization of sanitary landfill leachates

Composition of leachates from some sanitary landfills in Norway and in the U.S.A. is described. The wide range of compositions found was mainly attributed to the efficiencies of preventing water to enter the fills.

Organic acids were found to contribute almost 90% of the total organics in the high strength leachates. The ratio of carbonaceous BOD to COD increased significantly with the concentrations of organics. Thus a better biological treatability is expected for the high strength leachates. High concentrations of nitrogen mainly as ammonia prevailed in all the samples while the concentrations of phosphorus were low. Of the heavy metals, iron were high in all the leachates, zinc was found to be the next highest. The concentrations of chromium, nickel, copper, cadmium and lead were low.     

Slurry Phase Hydrogenation of CO2 to Methanol Using Supported In2O3 Catalysts as Promising Approach for Chemical Energy Storage

A promising approach for chemical energy storage from fluctuating renewable electricity is methanol synthesis from CO₂ and hydrogen in a slurry reactor concept, due to efficient heat storage and easy reactor control. In combination with a promising In₂O₃/ZrO₂ catalyst and mineral oil as carrier liquid, efficient methanol production under a wide range of changing process conditions is shown for the first time. A maximum methanol productivity of 2.1 g_MeOHg_In⁻¹h⁻¹ and multiple recycling stability of the catalyst and the carrier liquid was achieved, showing no significant decrease in methanol yields.     

Isotope-Guided Metabolomics Reveals Divergent Incorporation of Valine into Different Flavor Precursor Classes in Chives

Plants of the genus Allium such as chives, onions or garlic produce S-alk(en)yl cysteine sulfoxides as flavor precursors. Two major representatives are S-propenyl cysteine sulfoxide (isoalliin) and S-propyl cysteine sulfoxide (propiin), which only differ by a double bond in the C₃ side chain. The propenyl group of isoalliin is derived from the amino acid valine, but the source of the propyl group of propiin remains unclear. Here, we present an untargeted metabolomics approach in seedlings of chives (Allium schoenoprasum) to track mass features containing sulfur and/or ¹³C from labeling experiments with valine-¹³C₅ guided by their isotope signatures. Our data show that propiin and related propyl-bearing metabolites incorporate carbon derived from valine-¹³C₅, but to a much lesser extent than isoalliin and related propenyl compounds. Our findings provide new insights into the biosynthetic pathways of flavor precursors in Allium species and open new avenues for future untargeted labeling experiments.     

INES – An Interface Between Experiments and Simulation to Support the Development of Robust Process Designs

The development of chemical processes is based on both experiments and process simulations. Data evaluation and reconciliation, model development and validation, and design of experiments are essential steps in this procedure. The different tools and approaches available are usually not supported in an integrated way in the process developer's workflow. Therefore, a framework for process design was created and integrated in a tool box which supports process design comprehensively. It contains methods for data selection and reconciliation, sensitivity analysis, model validation and model adjustment.     

In situ–Directed Growth of Organic Nanofibers and Nanoflakes: Electrical and Morphological Properties

Organic nanostructures made from organic molecules such as para-hexaphenylene (p-6P) could form nanoscale components in future electronic and optoelectronic devices. However, the integration of such fragile nanostructures with the necessary interface circuitry such as metal electrodes for electrical connection continues to be a significant hindrance toward their large-scale implementation. Here, we demonstrate in situ–directed growth of such organic nanostructures between pre-fabricated contacts, which are source–drain gold electrodes on a transistor platform (bottom-gate) on silicon dioxide patterned by a combination of optical lithography and electron beam lithography. The dimensions of the gold electrodes strongly influence the morphology of the resulting structures leading to notably different electrical properties. The ability to control such nanofiber or nanoflake growth opens the possibility for large-scale optoelectronic device fabrication.