DEVELOPMENT OF NOVEL TEMPERATURE RESPONSIVE POLYMERIC SORBENTS AND THEIR APPLICATIONS IN WATER REMEDIATION

Water remediation utilizing sorption has found strong interest due to its inexpensiveness, universal nature and ease of operation. In particular, thermo-responsive sorbents consisting of N-isopropylacrylamide (NIPAAm) offer significant potential as “smart” and advanced materials to remove multiple aqueous pollutants. NIPAAm exhibits excellent thermo-responsiveness, which senses the external temperature variation and changes its swelling and sorption behaviors in a sharp and rapid manner. At the beginning of this work, an extensive review of literature has been compiled to provide a summary of NIPAAm-based thermo-responsive sorbents in water/wastewater remediation applications. Initially, we developed a novel approach to synthesize and characterize NIPAAm copolymeric hydrogels. Four different polyphenolic crosslinkers including curcumin multiacrylate (CMA), quercetin multiacrylate (QMA), 4,4’-dihydroxybiphenyl diacrylate (44BDA) and chrysin multiacrylate (ChryMA) were successfully incorporated into crosslinked hydrogels. Their temperature responsiveness and lower critical solution temperature (LCST) were characterized using swelling studies and differential scanning calorimetry (DSC). Increasing the crosslinker content resulted in a significant decrease in the swelling ratio and LCST, which was due to the increased crosslinking and hydrophobicity introduced by the polyphenolic crosslinkers. We also demonstrated the application of two sets of aforementioned crosslinked hydrogels (NIPAAm-co-CMA and NIPAAm-co-44BDA) as effective gel sorbents to capture phenol as a model contaminant. Temperature-dependent sorption was evaluated through a binding study of phenol at 10°C and 50°C. Significant enhancement in the sorption was observed at 50°C, and this can be attributed to the phase transition induced hydrophobic interactions between the copolymer gel and phenol. Moreover, the obtained hydrogels possessed facile and efficient regeneration ability in water at 10°C, without requiring harsh solvent treatment or high energy input. Building on the sorption behavior observed with crosslinked NIPAAm hydrogels, we extended the investigation to linear copolymer systems, and these were demonstrated as a temperature responsive flocculants. Here, NIPAAm copolymers consisting of 2-phenylphenol monoacrylate (2PPMA) were successfully developed as smart flocculants to remove metal oxide nanoparticles (e.g., Fe3O4, CeO2, TiO2). The incorporation of 2PPMA enhanced the flocculation at temperatures above the LCST (e.g., 50°C), which was due to the combined hydrophobicity of 2PPMA and NIPAAm. Overall, NIPAAm-based sorbents have a variety of applications in aqueous pollutant removal and are a promising class of materials for cost-effective water remediation technology

Heavy-Light Mesons on the Light Front

We study the heavy-light mesons within basis light-front quantization. The resulting mass spectra of $D$, $D_s$, $B$, and $B_s$ agree reasonably well with experiments. We also predict states which could be measured in the near future. In the light-front formalism, we calculate the light-front wave functions and additional experimental observables, such as parton distribution functions, distribution amplitudes, and decay constants by means of integrations over light-front wave functions. We also provide ratios of decay constants for selected pseudoscalar meson decays ($D_s$ to $D$ and $B_s$ to $B$) as they may prove to be theoretically more robust and more reliably determined in experiments. We find that our ratios are systematically smaller than existing experiment and other approaches by $5-18\%$.Comment: 15 pages, 19 figures, 2 table

From Facial Parts Responses to Face Detection: A Deep Learning Approach

In this paper, we propose a novel deep convolutional network (DCN) that achieves outstanding performance on FDDB, PASCAL Face, and AFW. Specifically, our method achieves a high recall rate of 90.99% on the challenging FDDB benchmark, outperforming the state-of-the-art method by a large margin of 2.91%. Importantly, we consider finding faces from a new perspective through scoring facial parts responses by their spatial structure and arrangement. The scoring mechanism is carefully formulated considering challenging cases where faces are only partially visible. This consideration allows our network to detect faces under severe occlusion and unconstrained pose variation, which are the main difficulty and bottleneck of most existing face detection approaches. We show that despite the use of DCN, our network can achieve practical runtime speed.Comment: To appear in ICCV 201

Relativistic bound states on the light front

We develop and apply a relativistic and non-perturbative approach to bound states and their properties on the light front in Quantum Chromodynamics (QCD). We investigate a Hamiltonian, derived in part from QCD, which features strongly interacting and confined quarks and apply it to heavy flavored mesons. This effective Hamiltonian is developed based on the light-front holographic QCD and an effective one-gluon-exchange interaction. We solve for the mass eigenstates and light-front wave functions (LFWFs) of this effective Hamiltonian using basis light-front quantization (BLFQ). This effective Hamiltonian was first implemented in the heavy quarkonium system where it provided a successful description of the mass spectrum and other physical observables. In this thesis, we will show that, with the least parameter fitting, we can also produce reasonable results for the unequal-mass heavy flavored mesons: $B_c$, $B$, $B_s$, $D$, and $D_s$. In particular, we calculated the mass spectra and corresponding light-front wave functions, illustrate their asymmetric features and employ them to calculate properties of experimental interest such as parton distribution amplitudes and functions. We further investigate the semileptonic decays of $B_c$ to charmonium. Since the gauge boson involved in the semileptonic decay needs to be in the timelike region, the conventional choice of frame, the Drell-Yan frame, is not suitable for these decays. Instead we adopt a general frame to tackle the kinematics. Due to the complex structure of the hadron current matrix that governs these decays, we employ more than one current component and LFWFs at different magnetic projections. There we also show the frame dependence that is due to the Fock sector truncation, that is our limited treatment of the mesons as quark - antiquark bound states omitting other possible contributions such as gluon excitations. We also report the dependence of calculated observables on parameters of the basis space, which we show how to minimize. As a further application of this approach, we apply it to the physical electron system in Quantum Electrodynamics (QED), which is treated as a relativistic electron which can emit and absorb a photon on the light front. We calculate the electromagnetic form factors and gravitational form factors of an electron, and compare our results with the light-front perturbation theory. This work provides insights into the challenges and promise of applying this light-front Hamiltonian approach to more complete treatments of QCD in the future

Human Body Digital Twin: A Master Plan

The human body DT has the potential to revolutionize healthcare and wellness, but its responsible and effective implementation requires consideration of various factors. This article presents a comprehensive overview of the current status and future prospects of the human body DT and proposes a five-level roadmap for its development. The roadmap covers the development of various components, such as wearable devices, data collection, data analysis, and decision-making systems. The article also highlights the necessary support, security, cost, and ethical considerations that must be addressed in order to ensure responsible and effective implementation of the human body DT. The proposed roadmap provides a framework for guiding future development and offers a unique perspective on the future of the human body DT, facilitating new interdisciplinary research and innovative solutions in this rapidly evolving field.Comment: 3 figure