Unexpected contraction of a zeolite framework upon isomorphous substitution of Si by Al

Isomorphous substitution of Si by Al in the framework of sodalites synthesized in ethylene glycol causes an unexpected contraction of the zeolite framework

Charge distribution and conformational stability effects of organic structure-directing agents on zeolite synthesis

While the use of the so-called organic structure-directing agents (OSDAs) is no stranger to zeolite synthesis at all, the effects of their charge distribution and conformational stability on the phase selectivity of the crystallization remain elusive. To systematically investigate these effects, we have prepared a series of imidazolium and pyrazolium derivatives with the same geometric shape but different positions of nitrogen atoms in the five-membered heterocyclic aromatic ring and used them as OSDAs for the synthesis of zeolites with pure-silica composition. Meaningful differences in the zeolite product were observed.11Ysciescopu

Dynamic Joint Scheduling of Anycast Transmission and Modulation in Hybrid Unicast-Multicast SWIPT-Based IoT Sensor Networks

The separate receiver architecture with a time- or power-splitting mode, widely used for simultaneous wireless information and power transfer (SWIPT), has a major drawback: Energy-intensive local oscillators and mixers need to be installed in the information decoding (ID) component to downconvert radio frequency (RF) signals to baseband signals, resulting in high energy consumption. As a solution to this challenge, an integrated receiver (IR) architecture has been proposed, and, in turn, various SWIPT modulation schemes compatible with the IR architecture have been developed. However, to the best of our knowledge, no research has been conducted on modulation scheduling in SWIPT-based IoT sensor networks while taking into account the IR architecture. Accordingly, in this paper, we address this research gap by studying the problem of joint scheduling for unicast/multicast, IoT sensor, and modulation (UMSM) in a time-slotted SWIPT-based IoT sensor network system. To this end, we leverage mathematical modeling and optimization techniques, such as the Lagrangian duality and stochastic optimization theory, to develop an UMSM scheduling algorithm that maximizes the weighted sum of average unicast service throughput and harvested energy of IoT sensors, while ensuring the minimum average throughput of both multicast and unicast, as well as the minimum average harvested energy of IoT sensors. Finally, we demonstrate through extensive simulations that our UMSM scheduling algorithm achieves superior energy harvesting (EH) and throughput performance while ensuring the satisfaction of specified constraints well.Comment: 29 pages, 13 figures (eps

Behavior of Connections Between SHS Columns & W-section Beams

Connections between SHS (Square Hollow Section) columns and W-section beams are generally fabricated by welding with or without endplates in the factory. These welded connections possess some finite degree of rotational stiffness which falls between fully rigid and ideally pinned joints. The influence of partially restrained connections on structural response not only changes the moment distribution but also increases frame drift. In this paper, a series of connection tests joining SHS column and W-section beam were executed and the test results compared with theoretical values. A method to utilize nonlinear moment-rotation relations of beam-to-column connections in steel framed structures is proposed. For the problem of contact in endplate-type connections, a simple and efficient method is also introduced