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In this study, we present extensive dissipative particle dynamics simulation studies of bottlebrush copolymers in solution having different grafting sequences: block and random. Distinct morphology of the grafting sequence-controlled bottlebrush copolymer micelles is investigated through backbone chain distribution along with the micelle structure. As a result, bottlebrush block copolymer (BBCP) micelles exhibit backbone chain primarily dependent on length scale of micelle size, while bottlebrush random copolymer (BRCP) exhibits side chain-dependent length scale. We further quantify the dependence of the micelles on the length scale of the backbone chain and side chain using the scaling relationship. We decouple the size of the micelles into core radius and corona thickness, and scaling behavior of these structures is quantitatively explained by the conformation of backbone chains and side chains. Also, the experimental scaling of BBCP and BRCP micelles in water shows consistent results of the sequence-dependent scaling exponents calculated by simulation. This work reveals the scaling behavior of the sequence-controlled graft copolymer micelles which potentially guides how one can modify the solution self-assembled complex micelles by controlling architecture and structure parameters of the bottlebrush copolymer.

Macroscopic assembly offers immense potential for constructing complex systems due to the high design flexibility of the building blocks. In such assembly systems, hydrogels are promising candidates for building blocks due to their versatile chemical compositions and ease of property tuning. However, two major challenges must be addressed to facilitate application in a broader context: the precision of assembly and the quantity of orthogonally matching pairs must both be increased. Although previous studies have attempted to address these challenges, none have successfully dealt with both simultaneously. Here, we propose topology-based design criteria for the selective assembly of hydrogel building blocks. By introducing the dual lock-and-key structures, we demonstrate highly precise assembly exclusively between the matching pairs. We establish principles for selecting multiple orthogonally matching pairs and achieve selective assembly involving simple one-to-one matching and complex assemblies with multiple orthogonal matching points. Moreover, by harnessing hydrogel tunability and the abundance of matching pairs, we synthesize complementary single-stranded structures for programmable assembly and successfully assemble them in the correct order. Finally, we demonstrate a hydrogel-based self-assembled logic gate system, including a YES gate, an OR gate, and an AND gate. The output is generated only when the corresponding inputs are provided according to each logic.

Enhancement of redox-reversibility in electroactive species has been studied because of fundamental interest and their importance for energy storage systems. Various electroactive molecules suffer from redox-irreversible behavior, and this is a critical reason for their exclusion as redox electrolytes in energy storage systems. In this article, we fully demonstrated that ascorbic acid (ASC), which is an abundant but redox-irreversible molecule, can become redox-reversible when it is confined in microporous carbon regimes. From a theoretical perspective, redox-reversibility in an electrochemical reaction coupled with an irreversible chemical process can be greatly enhanced due to kinetic acceleration toward the inverse direction of the chemical reaction by accumulation of products in the nanoconfined regime. However, the kinetic acceleration in a nanoconfined domain shows limitations for enhancing the redox-reversibility, which indicates that stabilization of the species undergoing an irreversible chemical process is another important factor for redox-reversibility enhancement. The origin of nanoporous confinement of ASC and its enhanced redox-reversibility was rationalized by molecular dynamics simulations. We found that ASC-clusters of a fully protonated ASC and its conjugated base formed inside carbon pores, which would be a main driving force for its confinement in microporous carbon networks. Lastly, we demonstrated a prototype energy storage device using redox-reversible ASC in microporous carbon as the half electrode, which shows the feasibility of ASC as a possible redox electrolyte in an aqueous energy storage system.

Shear alignment of the block copolymer (BCP) thin film is one of the promising directed self-assembly (DSA) methodologies for the unidirectional alignment of sub-10 nm microdomains of BCPs for next-generation nanolithography and nanowire-grid polarizers. However, because of the differences in the surface/interfacial energies at the top surface/bottom interface, the shear-induced ordering of BCP nanopatterns has been restricted to BCPs with spherical and cylindrical nanopatterns and cannot be realized for high-aspect-ratio perpendicular lamellar structures, which is essential for practical application to semiconductor pattern processes. It is still a difficult challenge to fabricate the unidirectional alignment in a short time over a large area. In this study, we propose an approach for combining the shear-rolling process with the filtered plasma treatment of BCP films for the fabrication of unidirectionally aligned and perpendicularly oriented lamellar nanostructures. This approach enables fabrication within 1 min on a 4 in scale. We treated filtered plasma on the BCP film for perpendicular orientation and executed the hot-rolling process with different roller and stage speeds. Large-scale shear was generated only at the location where the BCP film was in contact with both the roller and stage, effectively applying shear stress to a large area of the BCP film within a short time. The repeated application of this shear-rolling process can achieve a higher level of unidirectional alignment. Our aligned BCP vertical lamellae were used to fabricate a high-aspect-ratio sub-10-nm-wide metallic nanowire array viadry/wet processes. In addition, shear-rolling with chemoepitaxy patterns can achieve higher orientational order and lower defectivity.

Archimedean spirals in nanometer scale have shown remarkable plasmonic responses derived from their linear and rotational asymmetry. Despite the unique optical properties of nanoscale spirals, their applications have been limited due to the difficulty in fabricating large-scale arrays with uniform and systematic control of the morphology. Here, we report simulation results of spiral morphologies, which are used to design a scalable fabrication process for nanoscale spirals and predict their plasmonic responses. First, self-consistent field theory (SCFT) simulations were performed to design optimal templates to guide self-assembly into spiral morphologies. Using the SCFT results, we developed a scalable fabrication process, which is based on the micron-scale assembly of microspheres combined with glancing angle deposition and nanoscale assembly of block copolymers, to induce the formation of uniform nanospirals with diverse size, handedness, orientation, and winding number. Finally, finite-difference time-domain simulation results show linear dichroism and electric field intensity enhancement effects of these nanospirals, which are highly dependent on the winding number of the spirals, indicating the importance of precise control of the structural parameters.

We report the self-assembly of monolayer vesicles from Janus core–shell bottlebrush polymers. A route was developed to synthesize doubly grafted bottlebrush copolymers (DGBCPs) possessing A-b-B and B′-b-C side chains on a single repeating unit. Graft-through ring-opening metathesis polymerization of a norbornene moiety installed by single unit monomer insertion allowed us to place the backbone on any repeating unit of the core (B and B′) block. By decorating each core chain end with different chains via reversible addition–fragmentation chain transfer polymerization, we can obtain nanoobjects with an asymmetric B core and a phase-separated A/C shell. We demonstrate that polystyrene-branch-polystyrene′ and polylactide-b-polystyrene-branch-polystyrene′-b-poly(n-butyl acrylate) macromonomers can be successfully synthesized and polymerized to produce DGBCPs in high yields (81–94% conversion) with an absolute molar mass of 149–395 kg mol–1and a dispersity of 1.18–1.38. In a solvent slightly more selective to A than C, self-assembly of monolayer vesicles with diameter of <100 nm was observed by transmission electron microscopy. Dissipative particle dynamics simulations suggest that increasing the backbone length and moving the backbone toward the B′/C interface increases the backbone bending energy and favors a lower curvature. The spontaneous curvature appears to prefer a particular layer radius, avoiding bilayer formation.

The chemical degradation of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-based aqueous energy storage and catalytic systems is pH sensitive. Herein, we voltammetrically monitor the local pH (pHlocal) at a Pt ultramicroelectrode (UME) upon electro-oxidation of imidazolium-linker functionalized TEMPO and show that its decrease is associated with the greater acidity of the cationic (oxidized) rather than radical (reduced) form of TEMPO. The protons that drive the decrease in pH arise from hydrolysis of the conjugated imidazolium-linker functional group of 4-[2-(N-methylimidazolium)acetoxy]-2,2,6,6-tetramethylpiperidine-1-oxyl chloride (MIMAcO-T), which was studied in comparison with 4-hydroxyl-TEMPO (4-OH-T). Voltammetric hysteresis is observed during the electrode oxidation of 4-OH-T and MIMAcO-T at a Pt UME in an unbuffered aqueous solution. The hysteresis arises from the pH-dependent formation and dissolution of Pt oxides, which interact with pHlocalin the vicinity of the UME. We find that electrogenerated MIMAcO-T+significantly influences pHlocal, whereas 4-OH-T+does not. Finite element analysis reveals that the thermodynamic and kinetic acid–base properties of MIMAcO-T+are much more favorable than those of its reduced counterpart. Imidazolium-linker functionalized TEMPO molecules comprising different linking groups were also investigated. Reduced TEMPO molecules with carbonyl linkers behave as weak acids, whereas those with alkyl ether linkers do not. However, oxidized TEMPO+molecules with alkyl ether linkers exhibit more facile acid–base kinetics than those with carbonyl ones. Density functional theory calculations confirm that OH–adduct formation on the imidazolium-linker functional group of TEMPO is responsible for the difference in the acid–base properties of the reduced and oxidized forms.

Facing the escalating threat of viruses worldwide, the development of efficient sensor elements for rapid virus detection has never been more critical. Traditional point-of-care (POC) sensors struggle due to their reliance on fragile biological receptors and limited adaptability to viral strains. In this study, we introduce a nanosensor design for receptor-free virus recognitions using near-infrared (NIR) fluorescent single-walled carbon nanotubes (SWCNTs) functionalized with a poly(ethylene glycol) (PEG)-phospholipid (PEG-lipid) array. Three-dimensional (3D) corona interfaces of the nanosensor array enable selective and sensitive detection of diverse viruses, including Ebola, Lassa, H3N2, H1N1, Middle East respiratory syndrome (MERS), severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1), and SARS-CoV-2, even without any biological receptors. The PEG-lipid components, designed considering chain length, fatty acid saturation, molecular weight, and end-group moieties, allow for precise quantification of viral recognition abilities. High-throughput automated screening of the array demonstrates how the physicochemical properties of the PEG-lipid/SWCNT 3D corona interfaces correlate with viral detection efficiency. Utilizing molecular dynamics and AutoDock simulations, we investigated the impact of PEG-lipid components on 3D corona interface formation, such as surface coverage and hydrodynamic radius and specific molecular interactions based on chemical potentials. Our findings not only enhance detection specificity across various antigens but also accelerate the development of sensor materials for promptly identifying and responding to emerging antigen threats.

Control of the shape, size, internal structure, and uniformity of block copolymer (BCP) particles is crucial for determining their utility and functionality in practical applications. Here, we demonstrate a particle restructuring by solvent engineering (PRSE) strategy that combines membrane emulsification and solvent annealing processes to produce monodisperse BCP particles with controlled size, shape, and internal structure. A major advantage of the PRSE approach is the general applicability to different families of functional BCPs, including polystyrene-block-poly(1,4-butadiene) (PS-b-PB), polystyrene-block-poly(dimethylsiloxane) (PS-b-PDMS), and polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP). PRSE starts with the production of monodisperse BCP spheres in a wide range of particle sizes (from hundreds of nanometers to several tens of microns) using membrane emulsification, followed by successful transformation to shape-anisotropic BCP particles by solvent annealing under neutral wetting conditions. Particle size monodispersity was maintained during the PRSE process with shape transformations from sphere to ellipsoids (i.e., oblate and prolate). The approach was effective in controlling the aspect ratio (AR) of both prolate and oblate ellipsoids over wide ranges. These ARs were well-supported by free energy calculations based on a theoretical model describing particle elongation. Further investigation of the shape-transformation kinetics during the PRSE process revealed that the morphology transformation was driven by reorientation of BCP microdomains, with kinetics being strongly associated with the overall molecular weight of the BCP as well as the annealing time.

Self-assembly of block copolymers (BCPs) in evaporative emulsion provides a simple and effective route for the preparation of anisotropic particles with controlled shape and size. Understanding of thermodynamic phenomena associated with the bending/stretching of the BCP chains confined within the particles is necessary to enable precise control of the shape and microstructure of the particles. Herein, we report the systematic design of shape-anisotropic diblock copolymer (dBCP) particles based on a new theoretical model that includes entropic penalty associated with bending of dBCP chains upon deformation of the particles. First, we produced convex lens-shaped (oblate) and football-shaped (prolate) polystyrene-b-polydimethylsiloxane (PS-b-PDMS) particles, where the aspect ratios (AR, defined as the major axis length divided by minor axis length) were varied. Of note, the AR of the oblate particles increased almost linearly up to 10 as the particle size increased, whereas the increase of AR for the prolate particles was limited to 2.0. For oblate particles, the high bending energy of the curved cylinders at the periphery of a particle can be released by increasing the AR of particle. However, the relatively low bending energy of curved lamellae of prolate particles prevents the particles from having a high AR. Furthermore, our theoretical model that considers these bending energies successfully explains the experimental observations on the variation of particle shape depending on the particle size and the dBCP molecular weight.

The basic concept of warm mix asphalt (WMA) technologies is to reduce the asphalt binder viscosity, which allows the asphalt to attain a suitable viscosity to coat the aggregates and thus to compact asphalt mixtures at lower temperatures. A main concern for adding WMA additives to asphalt is that it might reduce the rutting resistance at high temperatures and the cracking resistance at low temperatures. To address these concerns, this article presents the impacts of various amounts of WMA additives on the viscosity and low-temperature cracking of asphalt binder. The test results at 135°C show that the viscosity of asphalt reduced significantly when 0.5 % of Additive B was added; the viscosity did not decrease when up to 1.0 % of Additive A was added. When the temperature was lowered to 120°C, however, a more drastic reduction in viscosity was observed when just 0.5 % of additives were added, and the viscosity remained relatively steady as the dosage was increased up to 3.0 %. These viscosity test results confirm that the higher amounts of WMA additives do not necessarily reduce the viscosity of asphalt binder. To characterize the low temperature property of the asphalt binder, the asphalt binder with WMA additives were tested using the asphalt binder cracking device (ABCD). As the WMA additives were increased from 0.5 % to 3.0 %, the cracking temperature increased slightly but remained steady near the cracking temperature of the virgin asphalt binder. The ABCD test results confirm that the cracking temperature of asphalt binder is not significantly affected by WMA additives.

Block copolymers (BCPs) confined in evaporative emulsions can assemble into ellipsoidal particles when solvent evaporation is faster than polymer diffusion within the droplet. Here, we report the synthesis of monodisperse, ellipsoidal polystyrene-block-1,4-polybutadiene (PS-b-PB) BCP particles with tunable aspect ratios (ARs) ranging from 1.0 to 2.2 and particle sizes ranging from 0.1 to 5 μm by membrane emulsification and subsequent solvent evaporation. The ratio of the propagation distance (lp) of ordered BCP domains perpendicular to the particle surface to the particle size (rBCP), or lp/rBCP, was found to be a critical parameter dictating the particle shape, where lp/rBCP> 1 yielded ellipsoids. We show that the AR of colloidal BCP ellipsoids can be precisely controlled by varying particle size (i.e., membrane pore size) and BCP molecular weight, as predicted by theoretical calculations of the free energy of particle elongation including three terms: (1) the interfacial energy between the two blocks of the BCP, (2) the entropic penalty associated with stretching of the BCP chains upon elongation of the particles, and (3) the surface energy between the BCP particles and the surrounding medium. Finally, using the resulting AR-controlled and highly monodisperse colloidal ellipsoids, we systematically investigated the effects of AR on the homogeneity of colloidal coatings obtained by drop-casting the ellipsoids into films.

The introduction of nanoparticle-mediated delivery and therapy has revolutionized cancer treatment approaches. However, there has been limited success in clinical trials because current approaches have not simultaneously satisfied therapeutic efficacy and biosafety criteria to an adequate degree. Here, we employ efficient macrophage-mediated exocytosis of elongated nanoparticles to facilitate their localization in tumor cells for cancer therapy and their transport to hepatocytes for hepatobiliary excretion. In vitro studies show that PEGylated high-aspect ratio gold nanoparticles exit macrophages more rapidly and remain in tumor cells longer, compared with low-aspect ratio and spherical nanoparticles. In tumors, high-aspect ratio nanoparticles tend to stay in tumor cells and escape from tumor-associated macrophages when they are taken up by those cells. In the liver, high-aspect ratio nanoparticles cleared by Kupffer cells mostly take the hepatobiliary excretion pathway through efficient Kupffer cell-hepatocyte transfer. Furthermore, we demonstrate that time-dependent localization of elongated gold nanoparticles toward tumor cells in tumor tissues enhances the overall phototherapeutic outcome. Engineering nanoparticles to modulate their exocytosis provides a new approach to improve cancer nanomedicine and pave the way toward clinical translation.

Shape and morphology of polymeric particles are of great importance in controlling their optical properties or self-assembly into unusual superstructures. Confinement of block copolymers (BCPs) in evaporative emulsions affords particles with diverse structures, including prolate ellipsoids, onion-like spheres, oblate ellipsoids, and others. Herein, we report that the evaporation rate of solvent from emulsions encapsulating symmetric polystyrene-b-polybutadiene (PS-b-PB) determines the shape and internal nanostructure of micron-sized BCP particles. A distinct morphological transition from the ellipsoids with striped lamellae to the onion-like spheres was observed with decreasing evaporation rate. Experiments and dissipative particle dynamics (DPD) simulations showed that the evaporation rate affected the organization of BCPs at the particle surface, which determined the final shape and internal nanostructure of the particles. Differences in the solvent diffusion rates in PS and PB at rapid evaporation rates induced alignment of both domains perpendicular to the particle surface, resulting in ellipsoids with axial lamellar stripes. Slower evaporation rates provided sufficient time for BCP organization into onion-like structures with PB as the outermost layer, owing to the preferential interaction of PB with the surroundings. BCP molecular weight was found to influence the critical evaporation rate corresponding to the morphological transition from ellipsoid to onion-like particles, as well as the ellipsoid aspect ratio. DPD simulations produced morphologies similar to those obtained from experiments and thus elucidated the mechanism and driving forces responsible for the evaporation-induced assembly of BCPs into particles with well-defined shapes and morphologies.

Fluorescent molecular rotors embedded in polymer matrices can probe the local changes in the dynamics of the polymer matrix (such as the glass transition of polymers near interfaces/surfaces) that are not accessible from macroscopic measurements. Yet, there is little consensus as to how the fluorescence data should be analyzed, what property the fluorescence intensity actually represents, and what are appropriate/optimal rotors for glass transition measurements. By experimentation with a model fluorescent rotor, farnesyl-(2-carboxy-2-cyanovinyl)-julolidine (FCVJ), and also re-analysis of data available in the literature for other types of molecular rotors, we investigated the correlation between the relaxation processes of photo-excited rotors and free volume changes in matrix polymers. The temperature dependences of the fluorescence intensities from FCVJ-doped polystyrene (PS), poly(vinyl acetate) (PVAc), and poly(isobutyl methacrylate) (PiBMA) materials across their glass transition temperatures (Tg) were successfully modeled using a free volume model which is based on the original theory of Loutfy that relates the fluorescence of a rotor probe to the free volume of the matrix, and the revised definition of the total free volume quantity proposed by Lipson and White (the Locally Correlated Lattice model-based free volume) that includes both the vibrational free volume and the excess free volume. Atomistic molecular dynamics simulation supports that the timescale of the vibrational motion of PS monomers is comparable to the intrinsic timescale of a rotor’s internal rotation known in the literature (on the order of picoseconds), and thus the rotation of a rotor is controlled by the friction from the hard-core volume (not by the friction from the vibrational volume) of the monomers. Measurements on FCVJ-loaded polystyrene–poly(ethylene glycol) (PS–PEG) micelles in water suggest that the PS core domain of the PS–PEG micelle has a broad distribution of glass transition temperatures; a quantitative analysis based on the free volume model enabled to estimate the actual range of Tg. These results allow us to conclude that fluorescent molecular rotors with a tendency toward rapid non-radiative (rotational) relaxation and bulky rotating subgroups (such as FCVJ) exhibit a strong coupling between the fluorescence of the rotor and the free volume of the matrix and are thus useful probes for Tgmeasurements.

CRISPR/Cas9 DNA editing creates a double-stranded break in the target DNA, which can frequently generate random insertion or deletion of bases (indels); a new genome editing approach combining Cas9 with a cytidine deaminase is described here, which corrects point mutations more efficiently than canonical Cas9, while avoiding double-stranded breaks and indel formation.

We report a simple and practical method for creating colloidal patchy particles with a variety of three-dimensional shapes viathe evaporation-induced assembly of polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) block copolymer (BCP) in an oil-in-water emulsion. Depending on the particle volume, a series of patchy particles in the shapes of snowmen, dumbbells, triangles, tetrahedra, and raspberry can be prepared, which are then precisely tuned by modulating the interfacial interaction at the particle/water interface using a mixture of two different surfactants. Moreover, for a given interfacial interaction, the stretching penalty of the BCPs in the patchy particles can be systematically controlled by adding P4VP homopolymers, which decreases the number of patches of soft particles from multiple patches to a single patch but increases the size of the patch. Calculations based on the strong segregation theory supported the experimental observation of various soft patchy particles and identified the underlying principles of their formation with tunable 3D structures.

This paper presents a mode shift control algorithm for reducing the variation in the driveshaft torque for a dual-mode power-split-type hybrid electric vehicle. To evaluate the shift characteristics of this hybrid electric vehicle, dynamic models for the hybrid electric vehicle powertrain were developed. Using the dynamic models, a mode shift performance simulator was developed, and simulations were performed. To analyse the shift characteristics during the mode shift, bond-graph models for the transient state were constructed, and state equations were derived. From the bond-graph models and state equations, it was found that the transient torque occurs because of the inertia torques of the first motor–generator and the second motor–generator. Based on the transient torque, a mode shift control algorithm was proposed, which compensates for the transient torque. To evaluate the performance of the proposed control algorithm, a test bench for the dual-mode power-split-type hybrid electric vehicle was developed. From the simulations and test results, it was found that the variation in the driveshaft torque was reduced by the proposed control algorithm, which provides improved shift quality.

A series of novel near-infrared-absorbing zinc phthalocyanines bearing donor–chromophore–acceptor/anchoring groups have been synthesized to investigate their influence on solar cell performance. With the aim of extending the absorption spectra while maintaining the minimization of aggregation by using 2,6-diphenylphenoxy bulky groups, the benzodithiadazole was used as an electron acceptor moiety and the carboxylic acid and the anhydride unit were adopted as an anchoring group. These dyes have been used as sensitizers in dye-sensitized solar cells, and their performance has been compared with that of phthalocyanine (Pc) sensitizer TT40, which has an ethynyl bridge between the anchoring carboxy group and the macrocycle. The new ZnPcs show an extended π-conjugated system which produces red shift in the absorption maximum of ca. 10 nm in comparison to that of TT40. Despite the red-shifted spectral response, these cells gave modest power conversion efficiencies of ca. 3% because of the lower lowest unoccupied molecular orbital level of the Pcs, which limits the electron injection from the dyes to the TiO2.

We demonstrate a dual-wavelength band optical frequency domain imaging (OFDI) system that provides high-resolution spectroscopic imaging with metallic nanoparticles as exogenous contrast agents. The local increase of the OFDI signal by elastic scattering from two different custom-fabricated nonspherical nanoparticles resonant at each wavelength band of the system was successfully detected, and we were able to distinguish and visualize the location of each of the nanoparticles in a scattering sample and in biological tissue.

Integrating coarse-grained reconfigurable architectures (CGRAs) into a System-on-a-Chip (SoC) presents many benefits as well as important challenges. One of the challenges is how to customize the architecture for the target applications efficiently and effectively without performing explicit design space exploration. In this article we present a novel methodology for incremental interconnect customization of CGRAs that can suggest a new interconnection architecture which is able to maximize the performance for a given set of application kernels while minimizing the hardware cost. In our methodology, we translate the problem of interconnect customization into that of inexact graph matching, and we devised a heuristic for A* search algorithm to efficiently solve the inexact graph matching problem. Our experimental results demonstrate that our customization method can quickly find application-optimized interconnections that exhibit 80% higher performance on average compared to the base architecture which has mesh interconnections, with little energy and hardware increase in interconnections and muxes.

Cold in-place recycling (CIR) is one of the most popular rehabilitation techniques in Iowa. The Iowa Department of Transportation has increased the minimum moisture criterion from 1.5% to 2.0% because many overlays have been successfully applied on the CIR layer with moisture contents above 2.0%. However, a contractor must make daily measurements of the moisture content with a nuclear gauge. It is difficult to achieve 2.0% moisture content during a rainy summer in Iowa. For the curing issue to be addressed systematically, the moisture contents and temperatures of one project of CIR with emulsified asphalt and four projects of CIR with foamed asphalt were monitored. Capacitance moisture and temperature sensors were embedded at the midpoint of the CIR layer to measure moisture contents and pavement temperature. A GeoGauge was used to measure the stiffness. The field data obtained from the embedded moisture sensors and from a weather station were used to develop a moisture prediction model as a function of the initial moisture content, CIR layer temperature, wind speed, and humidity. With the developed moisture prediction model, a contractor can predict optimal timing for placement of the wearing surface without continually measuring moisture contents of the CIR layer with a nuclear gauge. The stiffness of the CIR layer measured with the GeoGauge was found to continue to increase as the curing period increased, despite an increase in moisture content caused by rainfall. The stiffness measured by the GeoGauge steadily increased during the curing period until it reached a value of 30 MN/m. For the optimal timing of an overlay to be determined, the stiffness, rather than the moisture, of the CIR layer should be measured.

Cold in-place recycling (CIR) is one of the most popular rehabilitation techniques in Iowa. The Iowa Department of Transportation has increased the minimum moisture criterion from 1.5% to 2.0% because many overlays have been successfully applied on the CIR layer with moisture contents above 2.0%. However, a contractor must make daily measurements of the moisture content with a nuclear gauge. It is difficult to achieve 2.0% moisture content during a rainy summer in Iowa. For the curing issue to be addressed systematically, the moisture contents and temperatures of one project of CIR with emulsified asphalt and four projects of CIR with foamed asphalt were monitored. Capacitance moisture and temperature sensors were embedded at the midpoint of the CIR layer to measure moisture contents and pavement temperature. A GeoGauge was used to measure the stiffness. The field data obtained from the embedded moisture sensors and from a weather station were used to develop a moisture prediction model as a function of the initial moisture content, CIR layer temperature, wind speed, and humidity. With the developed moisture prediction model, a contractor can predict optimal timing for placement of the wearing surface without continually measuring moisture contents of the CIR layer with a nuclear gauge. The stiffness of the CIR layer measured with the GeoGauge was found to continue to increase as the curing period increased, despite an increase in moisture content caused by rainfall. The stiffness measured by the GeoGauge steadily increased during the curing period until it reached a value of 30 MN/m. For the optimal timing of an overlay to be determined, the stiffness, rather than the moisture, of the CIR layer should be measured.

Coarse-grained reconfigurable architectures (CGRAs) promise high performance at high power efficiency. They fulfil this promise by keeping the hardware extremely simple, and moving the complexity to application mapping. One major challenge comes in the form of data mapping. For reasons of power-efficiency and complexity, CGRAs use multibank local memory, and a row of PEs share memory access. In order for each row of the PEs to access any memory bank, there is a hardware arbiter between the memory requests generated by the PEs and the banks of the local memory. However, a fundamental restriction remains in that a bank cannot be accessed by two different PEs at the same time. We propose to meet this challenge by mapping application operations onto PEs and data into memory banks in a way that avoids such conflicts. To further improve performance on multibank memories, we propose a compiler optimization for CGRA mapping to reduce the number of memory operations by exploiting data reuse. Our experimental results on kernels from multimedia benchmarks demonstrate that our local memory-aware compilation approach can generate mappings that are up to 53% better in performance (26% on average) compared to a memory-unaware scheduler.

Exposure to trauma, post-traumatic stress disorder (PTSD), and depression, have been independently associated with leukocyte telomere length (LTL), a cellular marker of aging associated with mortality and age-related diseases. However, the joint contributions of trauma and its psychological sequelae on LTL have not been examined.

As more processing elements are integrated in a single chip, embedded software design becomes more challenging: It becomes a parallel programming for nontrivial heterogeneous multiprocessors with diverse communication architectures, and design constraints such as hardware cost, power, and timeliness. In the current practice of parallel programming with MPI or OpenMP, the programmer should manually optimize the parallel code for each target architecture and for the design constraints. Thus, the design-space exploration of MPSoC (multiprocessor systems-on-chip) costs become prohibitively large as software development overhead increases drastically. To solve this problem, we develop a parallel-programming framework based on a novel programming model called common intermediate code (CIC). In a CIC, functional parallelism and data parallelism of application tasks are specified independently of the target architecture and design constraints. Then, the CIC translator translates the CIC into the final parallel code, considering the target architecture and design constraints to make the CIC retargetable. Experiments with preliminary examples, including the H.263 decoder, show that the proposed parallel-programming framework increases the design productivity of MPSoC software significantly.

We investigated on the photoisomerization of azobenzene derivatives in liquid crystalline matrix that is 4-pentyl-4-bisphenyl carbonitrile (5CB) for holographic memory. In order to investigate of photoisomerization of azobenzene derivatives at the air/water interface, the azobenzene derivative having side chain monomer with alkyl chain was synthesized. The azobenzene derivatives in liquid crystalline matrix were characterized by the measurements of UV-vis spectroscopy, photorefractive index by two-beam coupling (2CB).

The electroreduction rates of Cr(OH2)63+and Cr(NH3)63+at the mercury–aqueous interface were monitored as a function of electrode potential in electrolytes containing univalent, divalent, or trivalent cations with systematically varying atomic number in order to scrutinize the role of the supporting electrolyte cation in the kinetics of these simple one-electron outer-sphere electrode reactions. The comparison between the corresponding rate responses for Cr(OH2)63+and Cr(NH3)63+reduction brought about by changing the supporting electrolyte cation is expected to provide information on the influence of the cation upon the potential profile in the double layer; despite the close structural and mechanistic similarity of the reactants, the transition state for the latter reaction appears to lie significantly closer to the electrode than that for the former process. The virtues of comparing rate responses at a constant electrode charge density rather than at a constant electrode potential are pointed out. It was found that the variations in the effective average potential at constant charge ding changes in the electrode potential derived from thermodynamic double-layer measurements. These results, along with the observed variations in the transfer coefficients for the two reactions, are semiquantitatively consistent with a model involving changes in the position of the oHp as the supporting electrolyte cation is altered, but are inconsistent with a model attributing the rate variations to cation specific adsorption.

In this paper, we present a hardware-software cosimulation environment for heterogeneous systems. To be an efficient and convenient verification environment for the rapid prototyping of heterogeneous systems consisting of hardware and software components, the environment supports (i) modular cosimulation, (ii) cosimulation acceleration, and (iii) integrated user interface and internal representation. For modular cosimulation, we treat software and hardware components as separate processes that communicate with each other only through inter-process communication. We generate interface model automatically and insert between software and hardware components. We can accelerate cosimulation through hardware-emulation using FPGAs which also supports our incremental system prototyping strategy. Finally, to provide an integrated user interface and internal representation consistent with various prototyping tasks, we modified and extended Ptolemy, a cosimulation and cosynthesis environment for heterogeneous systems. The benefits of our cosimulation environment are as follows: expandability of the environment, target architecture and protocol independence, interface transparency, seamless transition to cosynthesis, cosimulation speedup, and convenient cosimulation. As experimental examples, we cosimulated and prototyped several heterogeneous systems successfully, which shows that our environment can be a useful heterogeneous systems specification/verification environment for fast prototyping.

We developed a methodology, inspired by the folding of proteins, for the precision synthesis of hairy polymer nanoparticles. High-molar mass and narrowly dispersed graft copolymers were synthesized by graft-through ring opening metathesis polymerization, to incorporate a designated number of side chains and dimerizable cinnamic acid groups. Intrachain photodimerization collapsed the backbone and arrested it into a compact globular conformation, resulting in hairy nanoparticles topologically equivalent to a core cross-linked star polymer. The single-chain collapse process translates the molecular information written on the 1D graft copolymer into the 3D globular polymer nanoparticle, like protein folding. Unprecedented control over structural parameters was achieved, including the length, number, and composition of the side chains as well as cross-linking density. Different side chains formed distinct subdomains in the sterically congested nanoparticle state and further self-assembled into micellar aggregates in a selective solvent. Both experimental observations and computational simulations indicated that preorganization of the side chains in the block sequence produces subdomains which primarily follow the backbone length scale, while random sequences showed side chain-dependent scaling. Polymer nanoparticles with discrete multiple subdomains were produced by folding of the ternary block graft copolymers. Drastic differences in the self-assembly behavior of ABC- and ACB-sequenced nanoparticles indicate that the spatial organization of subdomains can be achieved by sequence control.

Procrastination is a widespread habit that has been understudied in the realm of health behaviors, especially sleep. This study aimed to examine the cross-sectional relationships between procrastination and multiple dimensions of sleep in a large national sample of US adolescents and young adults. A random sample of 8742 students from 11 US universities provided self-reports of procrastination (measured by the General Procrastination Scale-Short Form with scores ranging from 1 to 5) and sleep behaviors including social jetlag (the absolute difference between mid-sleep times on weeknights and weekend nights), sleep duration (mean weekly, weeknight, and weekend night), insomnia symptoms (trouble falling/staying asleep), daytime sleepiness, and sleep medication use. Multiple linear regression and Poisson regression models adjusted for socio-demographic and academic characteristics as well as response propensity weights. Higher levels of procrastination were significantly associated with greater social jetlag (β = 3.34 min per unit increase in the procrastination score; 95% CI [1.86, 4.81]), shorter mean weekly sleep duration (β = −4.44 min; 95% CI [-6.36, −2.52]), and shorter weeknight sleep duration (β = −6.10 min; 95% CI [-8.37, −3.84]), but not weekend night sleep duration. Moreover, procrastination was associated with insomnia symptoms (Relative Risk (RR) = 1.27; 95% CI [1.19, 1.37]) and daytime sleepiness (RR = 1.32; 95% CI [1.27, 1.38]), but not sleep medication use. The results were robust to adjustment for anxiety and depressive symptoms. Procrastination was associated with greater social jetlag, shorter sleep duration, and worse sleep quality. If causal, the results suggest that interventions to prevent and manage procrastination might help students to improve their sleep health.

A Korean contractor developed and used a cement treated Reclaimed Asphalt Pavement (RAP) containing asphalt emulsion and acryl polymer as base layer in Korea. Unfortunately, it was reported that the performance of the mixture was controversial by appearance of reflective and other cracking on the surface of the pavement. In the phase one study, main goals were evaluation of some mechanical properties as well as understanding the material category of this mixture. To achieve these goals, a series of literature reviews and laboratory tests were carried out including Marshall stability and flow, indirect tensile strength, water sensitivity, rutting resistance and compressive strength of both “Contractor mix” and Rhode Island (RI) pavement materials i.e. typical hot mix asphalt (HMA) and Portland Cement Concrete (PCC). According to the Asphalt Pavement Analyzer (APA) test results, it was observed that “Contractor mix” behaved similar to an elastic material at low temperatures while it tends to behave like a visco-elastic material at high temperatures to some extent. Also, it was resistance enough against the moisture damages and rutting phenomena, however, showed considerably lower compressive strength compared to PCC. Because of low compressive strength and probably high shrinkage of this mixture, it could be problematic to use it as base layer material and could affect pavement resistance against some distresses, particularly transverse and reflective cracking. Finally, because of high cement content and rigid behavior it was decided to model this material as concrete and/or cement treated RAP material in the second phase of this study.

Various bicyclic systems are available which contain both small and large ring moieties.