Providing service guarantees in high-speed switching systems with feedback output queuing

We consider the problem of providing per-customer service guarantees in a high-speed packet switch typically situated at the edge between a set of customers and a service provider network. As basic requirements, the switch should be scalable to high speeds per port, a large number of ports, and a large number of customers (macroflows) with independent guarantees. Existing scalable solutions are based on virtual output queuing, which is computationally complex when required to provide service guarantees for a large number of macroflows. We present a novel architecture for packet switching that provides support for such service guarantees. A cost-effective fabric with small external speedup is combined with a feedback mechanism that enables the fabric to be virtually lossless, thus avoiding packet drops indiscriminate of macroflows' behavior. Through analysis and simulation, we show that this architecture provides accurate support for service guarantees, has low computational complexity, and is scalable to very high port speeds.     

Determination of the antioxidant capacity: influence of the sample concentration on the measured values

The aim of the present analysis was to study the influence of the sample concentration on the measured antioxidant capacity, since such investigations are scarce but necessary to ensure the reproducibility of the results. Pure substances (ascorbic acid, gallic acid, Trolox^®, uric acid) and food extracts (strawberry nectar, tomato extract, white tea) were analysed using seven common antioxidant capacity assays (three versions of Trolox equivalent antioxidant capacity, TEAC; ferric reducing antioxidant power, FRAP; photochemiluminescence, PCL; oxygen radical absorbance capacity, ORAC and total phenolics assay). For all applied pure substances and in most of the assays effects of the sample concentration on the measured antioxidant capacity were observed. Since it remains speculative how sample concentration does affect the measured antioxidant capacity exactly, it is strongly recommended to use at least three sample concentrations for analysis to detect and to discuss concentration-dependent effects.     

Liquid–Liquid Diffusion‐Assisted Crystallization: A Fast and Versatile Approach Toward High Quality Mixed Quantum Dot‐Salt Crystals

Here, a new, fast, and versatile method for the incorporation of colloidal quantum dots (QDs) into ionic matrices enabled by liquid–liquid diffusion is demonstrated. QDs bear a huge potential for numerous applications thanks to their unique chemical and physical properties. However, stability and processability are essential for their successful use in these applications. Incorporating QDs into a tight and chemically robust ionic matrix is one possible approach to increase both their stability and processability. With the proposed liquid–liquid diffusion‐assisted crystallization (LLDC), substantially accelerated ionic crystallization of the QDs is shown, reducing the crystallization time needed by one order of magnitude. This fast process allows to incorporate even the less stable colloids including initially oil‐based ligand‐exchanged QDs into salt matrices. Furthermore, in a modified two‐step approach, the seed‐mediated LLDC provides the ability to incorporate oil‐based QDs directly into ionic matrices without a prior phase transfer. Finally, making use of their processability, a proof‐of‐concept white light emitting diode with LLDC‐based mixed QD‐salt films as an excellent color‐conversion layer is demonstrated. These findings suggest that the LLDC offers a robust, adaptable, and rapid technique for obtaining high quality QD‐salts.     

Folate content in frozen vegetarian ready meals and folate retention after different reheating methods

Folate content and retention were evaluated in 10 different precooked vegetarian ready meals before and after reheating. Folate was quantified using a validated high-performance liquid chromatography method. The only form of folate found was 5-methyltetrahydrofolate. Folate content in thawed ready meals varied from 23 to 81 μg/portion (400 g) on fresh weight basis. Products served with couscous and potatoes contained more folate than products served with rice. Folate retention during reheating was investigated in the microwave oven (900 W/5.5 min), in a saucepan on stove until the food reached 85 °C, and in oven (225 °C/40 min). The true vitamin retention varied for the three investigated portions as follows: on stove (63-93%), microwaving (55-89%) and in oven (50-92%). Our results indicate that folate content in the ready meals prior to reheating, contributed to 6-27% of the recommended intake (300 or 400 μg folate per day). After reheating folate content was significantly (P<0.05) reduced in some meals but were kept constant in others and folate content was reduced to 3-25% of the recommended value. No clear pattern in folate retention between different heating methods was seen. However, the meals with ingredients suggesting high concentrations of antioxidants were less prone to loose folate when heated since the antioxidants probably protected the folates.