Suchergebnisse

In this paper, a nanosecond voltage comparator with PECL logic for a photon-counting radiation imaging system is presented. To realize a high-speed comparison of four gamma detector channels in a limited board space, quad comparators MAX9602 with PECL logic are chosen. Each of the four channels is coupled with a PECL to CMOS converter ICS508, which exports CMOS logic data for later use in an FPGA. Simulated findings for cobalt-60 with intensities ranging from 30 Ci to 300 Ci show little count loss caused by using a comparator and indicate ideal propagation delays at all source intensities. While in the laboratory test using a PCB-level system, signals with pulse width less than 3 ns might be dropped, and dispersion of propagation delay occurs. Despite these, the performance is still satisfactory and can meet the requirements of practical applications, as demonstrated by an improved result of 0.9% in the contrast indicator model. Further studies to optimize the circuit design can be conducted to gain improvement.

As the catering sector has increasingly contributed to population-level salt intake, many countries have begun developing salt-reduction strategies for restaurants. This paper aims to provide an overview of global salt reduction policies in restaurants. Scientific papers and website materials were systematically searched from Web of Science, Science Direct, and PubMed, as well as official websites of government departments and organizations. A total of 78 full-text papers and grey literature works were included. From 58 countries and regions, 62 independent policies were identified, 27 of which were mandatory (3 with fines). The most common strategy was menu labeling, which was a component of 40 policies. Target setting (n = 23) and reformulation (n = 13) of dishes were also widely implemented. Other salt-reduction strategies included education campaign, chef training, toolkits delivery, table salt removal, media campaign, and government assistance such as free nutrition analysis and toolkits distribution. Most policies focused on chain restaurants. Evaluations of these policies were limited and showed inconsistent results, and more time is needed to demonstrate the clear long-term effects. Attention has been paid to salt reduction in restaurants around the world but is still at its early stage. The feasibility and effectiveness of the strategies need to be further explored.