Search

Large‐scale nuclear power plant production of iodine radionuclides (129I, 131I) pose huge threat in the events of nuclear disaster. Effective removal of radioiodine from nuclear waste is one of the most critical challenge because of the drawbacks of state‐of‐the‐art adsorbents such as high cost, low uptake capacity and non‐recyclability. Herein, two hydroxy‐functionalized (‐OH) hypercrosslinked polymers (HCPs), namely HCP‐91 and HCP‐92, have been synthesized and employed towards capture of iodine. High chemical stability along with synergistic harmony of high porosity and functionality of these materials makes them suitable candidates for capture of iodine from both vapor phase and water medium. Moreover, both the HCPs showed superior iodine removal performance from water in terms of fast kinetics and high removal efficiency (2.9 g g−1 and 2.49 g g−1 for HCP‐91 and HCP‐92 respectively). The role of functionality (‐OH groups) and porosity has been established with the help of HCP‐91, HCP‐92 and non‐functionalized biphenyl HCP for the efficient capture of I3− ions from water. In addition, both HCPs exhibited excellent selectivity and recyclability towards triiodide ions, rendering the potential of these materials towards real‐time applications. Lastly, Density functional theoretical studies revealed key insights and corroborate well with the experimental findings. [ABSTRACT FROM AUTHOR]

Fabricating new and efficient materials aimed at containment of water contamination, in particular removing toxic heavy metal based oxo‐anions (e. g. CrO42−, TcO4−) holds paramount importance. In this work, we report two new highly stable imidazolium based ionic porous organic polymers (iPOPs) decorated with multiple interaction sites along with electrostatics driven adsorptive removal of such oxo‐anions from water. Both the iPOPs (namely, iPOP‐3 and iPOP‐4) exhibited rapid sieving kinetics and very high saturation uptake capacity for CrO42− anions (170 and 141 mg g−1 for iPOP‐3 and iPOP‐4 respectively) and ReO4− (515.5 and 350.3 mg g−1 for iPOP‐3 and iPOP‐4 respectively), where ReO4− anions being the non‐radioactive surrogative counterpart of radioactive TcO4− ions. Noticeably, both iPOPs showed exceptional selectivity towards CrO42− and ReO4− even in presence of several other concurrent anions such as Br−, Cl−, SO42−, NO3− etc. The theoretical binding energy calculations via DFT method further confirmed the preferential interaction sites as well as binding energies of both iPOPs towards CrO42− and ReO4− over all other competing anions which corroborates with the experimental high capacity and selectivity of iPOPs toward such oxo‐anions. [ABSTRACT FROM AUTHOR]

In this paper, we study the problem of mobile target tracking using the fewest number of mobile trackers for two different types of targets. Given the target trajectories and the period of observation, we propose techniques to compute the minimum number of trackers and their trajectories required to track all mobile targets. Two classes of mobile targets are considered in this paper: 1) targets that need tracking for the entire duration of observation and 2) targets that need tracking at least once during the period of observation. We show that even when target trajectories are known in advance, the problem is computationally hard, i.e., NP-complete. We formulate the problem as a network flow problem and propose algorithms for its solution. We evaluate the performance of our algorithms through simulation and study the impact of parameters such as the speed and sensing range of the trackers. [ABSTRACT FROM AUTHOR]

Graphical abstract A post-synthetically modified MOF has been employed for sensing of bisulfite anion in water medium. This MOF based selective turn on response towards bisulfite anion has also been demonstrated in presence of concurrent anions. Abstract A metal–organic framework (MOF) based luminescent probe was strategically designed for selective recognition of bisulfite anion (HSO 3 −) in water medium. The chemically stable MOF, NH 2 -MIL-68(In) was decorated with specific recognition site via post synthetic modification. The post synthetically modified MOF showed a selective turn on response towards bisulfite anion retaining its structural integrity. This selective recognition is also persistent even in presence of competing anions. [ABSTRACT FROM AUTHOR]

Current practices of fault-tolerant network design ignore the fact that most network infrastructure faults are localized or spatially correlated (i.e., confined to geographic regions). Network operators require new tools to mitigate the impact of such region-based faults on their infrastructures. Utilizing the support from the U.S. Department of Defense, and by consolidating a wide range of theories and solutions developed in the last few years, the authors of this paper have developed Raptor, an advanced Network Planning and Management Tool that facilitates the design and provisioning of robust and resilient networks. The tool provides multi-faceted network design, evaluation, and simulation capabilities for network planners. Future extensions of the tool currently being worked upon not only expand the tool’s capabilities, but also extend these capabilities to heterogeneous interdependent networks such as communication, power, water, and satellite networks. [ABSTRACT FROM AUTHOR]

Two porous hydrogen-bonded organic frameworks (HOFs) based on arene sulfonates and guanidinium ions are reported. As a result of the presence of ionic backbones appended with protonic source, the compounds exhibit ultra-high proton conduction values ( σ) 0.75× 10−2 S cm−1 and 1.8×10−2 S cm−1 under humidified conditions. Also, they have very low activation energy values and the highest proton conductivity at ambient conditions (low humidity and at moderate temperature) among porous crystalline materials, such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs). These values are not only comparable to the conventionally used proton exchange membranes, such as Nafion used in fuel cell technologies, but is also the highest value reported in organic-based porous architectures. Notably, this report inaugurates the usage of crystalline hydrogen-bonded porous organic frameworks as solid-state proton conducting materials. [ABSTRACT FROM AUTHOR]

Distributed storage of data files in different nodes of a network enhances its fault tolerance capability by offering protection against node and link failures. Reliability is often achieved through redundancy in one of the following two ways: (i) storage of multiple copies of the entire file at different locations (nodes) or (ii) storage of file segments (not entire files) at different node locations. In the (N,K) file distribution scheme, N file segments from a file F are created in such a way that it is possible to reconstruct the entire file, just by accessing any K ≤ N segments. For the reconstruction scheme to work, it is essential that the K segments of the file are stored in nodes that are connected in the network. However, in the event of node/link failures, the network might become disconnected (i.e., split into several connected components). We focus on node failures that are spatially correlated or region based. Such failures are often encountered in disaster situations or natural calamities where only the nodes in the disaster zone are affected. The first goal of this research is to design a least cost file storage scheme to ensure that no matter which region is destroyed; resulting in fragmentation of the network, a largest connected component of the residual network will have enough file segments with which to reconstruct the entire file. In case the least cost to ensure this objective is within the allocated budget, the storage design will be all region fault-tolerant (ARFT). In case the least cost exceeds the allocated budget, design of an ARFT file storage system design is impossible. The second goal of this research is to design file storage schemes that will be maximum region fault-tolerant within the allocated budget. The third goal of this research is to investigate the impact of the coding parameters N and K on storage requirements for ensuring all region or maximum region fault-tolerant design. We provide approximation algorithms for the problems and evaluate their performance through simulation using two real networks and compare their results to the optimal solutions obtained using Integer Linear Program. The simulation results demonstrate that the approximation algorithms almost always produce near optimal results in a fraction of the time needed to find the optimal solution. [ABSTRACT FROM AUTHOR]

Keywords: anions; DFT calculations; dual capture; hyper-cross-linked polymers; radioiodine; water remediation EN anions DFT calculations dual capture hyper-cross-linked polymers radioiodine water remediation 1 1 1 11/29/22 20221101 NES 221101 B The cover feature image illustrates b a family of hydroxy-functionalized hypercrosslinked polymers (HCPs) toward efficient capture of radioactive iodine from both vapour and water phase. Anions, DFT calculations, dual capture, hyper-cross-linked polymers, radioiodine, water remediation Cover Feature: Hydroxy-Functionalized Hypercrosslinked Polymers (HCPs) as Dual Phase Radioactive Iodine Scavengers: Synergy of Porosity and Functionality (ChemPlusChem 11/2022). [Extracted from the article]