Nanocomposites and methods for synthesis and use thereof

Nanocomposite compositions and methods of synthesis of the compositions are described. In particular, liquid crystal-functionalized nanoparticles, liquid crystal-templated nanoparticles, nanocomposite compositions including the nanoparticles, and composite compositions including the nanocomposites are detailed.Board of Regents, University of Texas Syste

An ultra melt-resistant hydrogel from food grade carbohydrates

© 2017 The Royal Society of Chemistry. We report a binary hydrogel system made from two food grade biopolymers, agar and methylcellulose (agar-MC), which does not require addition of salt for gelation to occur and has very unusual rheological and thermal properties. It is found that the storage modulus of the agar-MC hydrogel far exceeds those of hydrogels from the individual components. In addition, the agar-MC hydrogel has enhanced mechanical properties over the temperature range 25-85 °C and a maximum storage modulus at 55 °C when the concentration of methylcellulose was 0.75% w/v or higher. This is explained by a sol-gel phase transition of the methylcellulose upon heating as supported by differential scanning calorimetry (DSC) measurements. Above the melting point of agar, the storage modulus of agar-MC hydrogel decreases but is still an elastic hydrogel with mechanical properties dominated by the MC gelation. By varying the mixing ratio of the two polymers, agar and MC, it was possible to engineer a food grade hydrogel of controlled mechanical properties and thermal response. SEM imaging of flash-frozen and freeze-dried samples revealed that the agar-MC hydrogel contains two different types of heterogeneous regions of distinct microstructures. The latter was also tested for its stability towards heat treatment which showed that upon heating to temperatures above 120 °C its structure was retained without melting. The produced highly thermally stable hydrogel shows melt resistance which may find application in high temperature food processing and materials templating

The effects of low dissolved oxygen concentrations on diving behavior and lactate accumulation in \u3ci\u3eLithobates pipiens\u3c/i\u3e

Dissolved oxygen (DO) concentrations in bodies of water can differ based on geographic location, time of day, or even climate change. Because frogs acquire approximately 20% of their oxygen across the skin, decreases in DO could negatively affect diving behavior by increasing reliance on anaerobic metabolism and formation of lactate. To evaluate this possibility, we measured pulmonary and cutaneous oxygen exchange as well as blood lactate levels before and after a 30-minute dive period under both saturated DO (8.341 ± 0.042 mg/L) and low DO conditions (3.918 ± 0.597 mg/L). Although frogs diving in a low oxygen environment tended to accumulate slightly more lactate, which would indicate a shift toward anaerobic metabolism, the trend was not significant (t(8) = 1.86, p = 0.525). A reduction in cutaneous O2 gas exchange was observed to be significant (t(8) = 1.86, p = 0.0015) following a forced dive. However, cutaneous O2 gas exchange only makes up a miniscule amount of the total pulmocutaneous gas exchange; therefore, would have little effect on lactate accumulation. In conclusion, low DO water does not appear to influence diving behavior or lactate accumulation in a biologically significant way for this species. However, we acknowledge the possibility that low DO water may have a more profound effect during dives of longer durations

Sources and sinks of carbon dioxide in populous Asia

The recently concluded 21st Conference of the Parties (COP21) under the United Nations Framework Convention on Climate Change (UNFCCC) agreed to limit the increase in global temperature to less than 2oC above pre-industrial levels, with a more aspirational target of 1.5oC. Achieving these policy goals will require extraordinary input from the scientific community to define anthropogenic emission targets that account for natural biosphere sources and sinks of carbon dioxide (CO2), consistent with the climate targets. Asian countries, being densely populated and emerging global economic powers, are key players in defining future emission trajectories. The average fossil emissions from the three regions are estimated to be 2.4, 0.5 and 0.3 PgC yr-1 for East, South and Southeast Asia, respectively, and have increased by 67, 58 and 33% over the period 2003-2012. Here, we estimate land biosphere CO2 fluxes using: 1) simulations of terrestrial ecosystem models driven with global and regional atmospheric and climate observations and 2) atmospheric CO2 inverse models. Based on observations of atmospheric CO2 and inverse models, we show that on average over the period 2003 - 2012, the land biosphere (excluding fossil fuel emissions) in the three Asian regions in our study is either a CO2 sink (0.35 PgC yr-1 in East Asia) or source neutral (South and Southeast Asia). Consistently, our terrestrial ecosystem modeling suggests that the land biosphere of South and Southeast Asia were nearly neutral, but disagrees for East Asia

Radiation pressure in galactic disks: stability, turbulence, and winds in the single-scattering limit

The radiation force on dust grains may be dynamically important in driving turbulence and outflows in rapidly star-forming galaxies. Recent studies focus on the highly optically-thick limit relevant to the densest ultra-luminous galaxies and super star clusters, where reprocessed infrared photons provide the dominant source of electromagnetic momentum. However, even among starburst galaxies, the great majority instead lie in the so-called "single-scattering" limit, where the system is optically-thick to the incident starlight, but optically-thin to the re-radiated infrared. In this paper we present a stability analysis and multidimensional radiation-hydrodynamic simulations exploring the stability and dynamics of isothermal dusty gas columns in this regime. We describe our algorithm for full angle-dependent radiation transport based on the discontinuous Galerkin finite element method. For a range of near-Eddington fluxes, we show that the medium is unstable, producing convective-like motions in a turbulent atmosphere with a scale height significantly inflated compared to the gas pressure scale height and mass-weighted turbulent energy densities of $\sim 0.01-0.1$ of the midplane radiation energy density, corresponding to mass-weighted velocity dispersions of Mach number $\sim 0.5-2$. Extrapolation of our results to optical depths of $10^3$ implies maximum turbulent Mach numbers of $\sim20$. Comparing our results to galaxy-averaged observations, and subject to the approximations of our calculations, we find that radiation pressure does not contribute significantly to the effective supersonic pressure support in star-forming disks, which in general are substantially sub-Eddington. We further examine the time-averaged vertical density profiles in dynamical equilibrium and comment on implications for radiation-pressure-driven galactic winds.Comment: 19 pages, 15 figures, submitted to MNRAS. Comments welcom

Wind Blade Manufacturing for the Cal Poly Wind Power Club

The Cal Poly Wind Power Club is entering the 2021 Collegiate Wind Competition (CWC) in June. Last year, three senior project teams were assigned to collaborate and assist the club with the pitching mechanism, the rotor balancing, and the manufacturing process. As the manufacturing team, the goal of our project was to design a manufacturing process for the bladegeometry given. The manufacturing process was required to meet the team’s expectations and CWC’s performance requirements to place highly in the competition taking place in June 2021.These expectations included creating a manufacturing process that is repeatable and reliable for future competitions. The manufactured blades had to be dimensionally accurate up to less than one percent error between each of the three blades. The blades also needed to be as light as possible to be efficient, thus the blades needed to be less than half a pound each. The manufactured blades also needed to be as smooth as 0.25 microns to ensure aerodynamic performance is not compromised. Our finalized process met the requirements for almost all these requirements. The dimensional accuracy of the blades is less than one percent error between the blades, however, some additional changes will be needed for future blades which be explained later in the report. The finalized blades far surpass the goals given by the WPC, only weighing 1/8 of a pound each compared to the half pound goal. Lastly the surface roughness of the blades did not meet the 0.25-micron requirement, however, we believe that the final design reaches a smoothness that will be acceptable for the competition. Solutions to make the blades smoother are also given in the report if the WPC believes the finalized blades do not meet their requirements

A Novel Massage Therapy Technique for Management of Chronic Cervical Pain: A Case Series

Background: Neck pain is a generalized condition resulting from a complex etiology with presentation of a wide variety of symptoms. Neck pain is most often accompanied by decreased range of motion (ROM), muscle and joint stiffness, and limitations in functional capabilities. This condition may result in significant personal and societal burden. Purpose: We evaluated the effectiveness of a novel massage therapy intervention by following the treatment regimen and outcomes of two patients experiencing chronic neck pain. Participants: Two patients (46 and 53 years old) experienced chronic (>5 years) neck pain. Both patients reported pain, limited ROM, and muscle and joint stiffness. Additionally, the first patient reported a lack of sleep, and both patients stated their pain interfered with their quality of life and activities of daily living. Intervention: Patients received the Integrative Muscular Movement Technique (IMMT) intervention approximately twice a week for a total of eight treatments, each approximately 20 minutes in duration. Results: Both patients experienced a reduction in pain and an increase in cervical ROM in flexion, extension, rotation, and sidebending. The first patient also reported an increased ability to sleep. Both patients reported an increased ability to perform activities of daily living, including work-related responsibilities. Conclusions: For the two patients included in this report, therapist observations and patient reports indicate that inclusion of the IMMT treatment in a treatment regimen for chronic neck pain may lead to decreased pain and increased cervical ROM. These positive effects of the IMMT intervention may have a role in enhancing functional outcomes of these patients

Structuring and calorie control of bakery products by templating batter with ultra melt-resistant food-grade hydrogel beads

This journal is © The Royal Society of Chemistry. We report the use of a temperature insensitive, food-grade hydrogel to reduce the caloric density of pancakes that were prepared at temperatures much higher than the boiling point of water. This cheap, facile method utilises a mixed agar-methylcellulose hydrogel, which was blended to produce a slurry of hydrogel microbeads. The pancake batter was mixed with a controlled volume percentage of slurry of hydrogel beads and cooked. From bomb calorimetry experiments, the composites were found to have a reduced caloric density that reflects the volume percentage of hydrogel beads mixed with the batter. Using this procedure, we were able to reduce the caloric density of pancakes by up to 23 ± 3% when the volume percentage of hydrogel beads initially used was 25%. The method is not limited to pancakes and could potentially be applied to various other food products. The structure and morphology of the freeze-dried pancakes and pancake-hydrogel composites were investigated and pores of a similar size to the hydrogel beads were found, confirming that the gel beads maintained their structure during the cooking process. There is scope for further development of this method by the encapsulation of nutritionally beneficial or flavour enhancing ingredients within the hydrogel beads

Teraflop per second gravitational lensing ray-shooting using graphics processing units

Gravitational lensing calculation using a direct inverse ray-shooting approach is a computationally expensive way to determine magnification maps, caustic patterns, and light-curves (e.g. as a function of source profile and size). However, as an easily parallelisable calculation, gravitational ray-shooting can be accelerated using programmable graphics processing units (GPUs). We present our implementation of inverse ray-shooting for the NVIDIA G80 generation of graphics processors using the NVIDIA Compute Unified Device Architecture (CUDA) software development kit. We also extend our code to multiple-GPU systems, including a 4-GPU NVIDIA S1070 Tesla unit. We achieve sustained processing performance of 182 Gflop/s on a single GPU, and 1.28 Tflop/s using the Tesla unit. We demonstrate that billion-lens microlensing simulations can be run on a single computer with a Tesla unit in timescales of order a day without the use of a hierarchical tree code.Comment: 21 pages, 4 figures, submitted to New Astronom

Hierarchically porous composites fabricated by hydrogel templating and viscous trapping techniques

© 2017 Elsevier Ltd Two methods for the preparation of hierarchically porous composites have been developed and explored. The first involved templating mixed slurries of hydrogel beads with two different average bead size distributions with gypsum slurry which allows for precise control over the porosity, pore size distributions and hierarchical microstructure of the hardened composite after the evaporation of the water from the hydrogel beads. The other technique utilised the viscosity of methylcellulose solution to suspend gypsum particles as they form an interlocked network. By varying the volume percentage of methylcellulose solution used, it is possible to control the porosity of the dried sample. The mechanical and thermal insulation properties of the composites as a function of both their porosity and pore size were investigated. Both methods demonstrate an inexpensive approach for introducing porosity in gypsum composites which reduces their thermal conductivity, improves their insulation properties and allows economic use of the matrix material whilst controlling their mechanical properties. Such composites allow for tuneable porosity without significantly compromising their strength which could find applications in the building industry as well as structuring of other composites for a variety of consumer products