Systems and methods for converting biomass to biocrude via hydrothermal liquefaction

Systems and processes of providing novel thermal energy sources for hydrothermal liquefaction (HTL) reactors are described herein. According to various implementations, the systems and processes use concentrated solar thermal energy from a focused high-energy beam to provide sufficient energy for driving the HTL biomass-to-biocrude process. In addition, other implementations convert biowaste, such as municipal biosolids and grease and food waste, to biocrude using anaerobic digesters, and a portion of the biogas generated by the digesters is used to produce the thermal and/or electrical energy used in the HTL reactor for the biomass-to-biocrude process. Furthermore, alternative implementations may include a hybrid system that uses biogas and solar radiation to provide sufficient thermal energy for the HTL reactor.Board of Regents, University of Texas Syste

Microorganism Cultivation Platform for Human Life Support

A life support system for providing a growth medium for at least one photosynthetic micro-organism and for converting CO2 to O2, with reduced water use that is as low as about 4 percent of the corresponding amount of water normally required for conventional micro-organism growth. The system includes a liquid transport capillary channel, a mixed culture photosynthetic biofilm and a liquid transport substrate that is positioned between and contiguous to the capillary channel and the biofilm, where the liquid transport rate is adjustable by adjustment of the local humidity. Approximately uniform radiation is received by the biofilm and contributes to microorganism growth

Enhanced self-collimation effect by low rotational symmetry in hexagonal lattice photonic crystals

In this study, we present the design of a photonic crystal (PC) structure with a hexagonal lattice, where adjustments to the PC unit cell symmetry reveal an all-angle self-collimation (SC) effect. By optimizing opto-geometric parameters, such as the rotational angle of auxiliary rods and adjacent distances, we analyze the SC property in detail, leveraging group velocity dispersion (GVD) and third-order dispersion (TOD) characteristics. We also investigate the relationship between symmetry properties and their influence on dispersion characteristics. Through symmetry manipulation, we gain a comprehensive understanding of the underlying mechanisms governing light collimation and confinement in the proposed configurations. The PC structure with a $C_1$ symmetry group exhibits all-angle SC effect within the range of $a/\lambda=0.652$ and $a/\lambda=0.668$ normalized frequencies, with a bandwidth of $\Delta \omega/\omega_c = 2.4\%$. Further breaking the symmetry, transforming from $C_1$ to $C_2$ group symmetry, enhances the SC bandwidth to $\Delta \omega/\omega_c =6.5\%$ and reveals the perfect linear equi-frequency contours (EFC) at two different frequency bands: all angle SC between $a/\lambda = 0.616$ and $a/\lambda = 0.656$ normalized frequencies in the 4th transverse magnetic (TM) band and between $a/\lambda=0.712$ and $a/\lambda=0.760$ in the 5th TM band. Additionally, we propose a composite/hybrid PC structure resembling $C_2$ group symmetry, where two auxiliary rods are replaced by rectangular photonic wires with the same refractive index and width equal to the diameter of auxiliary rods. This hybrid structure exhibits an all-angle SC effect with an operating bandwidth of $\Delta \omega/\omega_c =11.7\%$, displays near-zero GVD and TOD performance and offers enhanced robustness against potential fabrication precision issues

Clinical and Laboratory Characteristics of Hyperprolactinemia in Children and Adolescents: National Survey

Conclusion: We present the largest cohort of children and adolescents with hyperprolactinemia in the literature to date. Hyperprolactinemia is more common in females and cabergoline is highly effective and practical to use in adolescents, due to its biweekly dosing. Indications for surgery in pediatric cases need to be revised

A simple single-mode fiber loss measurement scheme in the C-band based on fiber loop-cavity ringdown spectroscopy

An extremely sensitive and simple fiber loop-cavity ringdown spectroscopy (FL-CRDS) setup has been designed based on a turn-key nanosecond pulse laser source operating at 1535 nm. The system sensitivity is demonstrated to be approximately 0.01 dB after extracting the characteristic macrobend loss curve of a standard single mode fiber (SMF-28). The experiment demonstrated that the oscillatory behavior in the rapid loss due to the increasing curvature could be seen for single turn bare fibers with radii of curvature from 10-20 mm. Since the wavelength of laser lies in the range of the conventional window, known as C-band, the demonstrated scheme may suggest the use of these techniques in versatile applications where quick results are necessary without the system complexity

Rheological Properties of Dry Water

This study reports the rheological properties of the novel material “dry water” which contains about 98% by weight water but resembles a dry powder. Dry water is a water-in-air inverse foam which consists of microscopic water droplets encapsulated with hydrophobic fumed-silica nanoparticles. This novel material offers a large surface to volume ratio on the order of 2 × 105 m2/m3 for the gas and water phases. Thus, it provides a convenient medium for surface area limited processes and finds applications from cosmetics to gaseous fuel storage. In this study both steady and dynamic rheological properties of dry water were measured. In particular, the elastic (G′) and viscous (G″) moduli, and the complex dynamic shear viscosity (η*) were recovered from experimental data. Results showed that both the elastic and viscous moduli decreased with increasing strain at strains larger than 4%, and both moduli are weak functions of rotational frequency. Complex dynamic shear viscosity decreased with strain and rotational frequency. When compared with the studies in literature, rheological experiments and obtained results indicated that dry water behaves as a gel rheologically under the investigated conditions

Thermal radiation transport in a fluidized dry water system

This paper reports a numerical study on thermal radiation transport in a novel material called dry water. Dry water is a water-in-air inverse foam which consists of micrometer-sized water droplets encapsulated by hydrophobic fumed-silica nanoparticles. First, the size distribution of dry water was measured using a particle size analyzer. Then, the radiation characteristics of dry water were obtained using the Mie theory for coated spheres. One-dimensional, steady radiative transport in fluidized dry water system was modeled using the radiative transport equation (RTE) and was solved spectrally with the discrete ordinates method. The effects of silica coating and water droplet size as well as the volume fraction of dry water particles on reducing radiative heat transfer were studied parametrically. The results obtained using the size distributions from experimental measurements at a volume fraction of 10(-4) showed that dry water reduced the local radiative heat flux by more than 60% with respect to that by silica particles alone whereas its performance was comparable to that of fine water mists. Moreover, reduction of the diameter of dry water particles from 150 to 50 mu m and increasing their volume fraction from 10(-4) to 10(-3) decreased the radiative heat flux by 45% and 67%, respectively. Dry water is a novel and unique material that does not require high pressure fluid lines for producing fine mists and features a silica shell that can serve to encapsulate water soluble compounds, retard water evaporation from the core as well as increase scattering. With these unique features, dry water finds diverse engineering applications serving as a base for photo-catalytic nanoreactors, gas and chemical storage and delivery systems, as well as alternative mist systems in firefighting. (C) 2013 Elsevier Ltd. All rights reserved

Dissociation of Carbon Dioxide Using a Microdischarge Plasma Reactor

This paper reports an experimental study on dissociation of carbon dioxide using a microdischarge plasma reactor at ambient conditions. Carbon dioxide contributes to more than 80% of the greenhouse gas emissions in United States. The microdischarge plasmas can be a very promising method in dissociating gases, including carbon dioxide, due to their lack of need for catalysts, operating at temperatures lower than conventional thermochemical dissociation processes and ease of operation. A microhollow cathode discharge plasma reactor was designed and prototyped for CO2 dissociation. The reactor included metal electrodes that were attached to both sides of a dielectric material with a micro-size through hole. The electrodes and the dielectric material were placed perpendicular to flow direction for dissociation to occur as carbon dioxide passed through the hole. A set of experiments were conducted to investigate the effect of flow rate and applied voltage on the composition of the products, energy conversion efficiency and CO2-to-CO conversion yield of the microdischarge plasma reactor. Temperature of reactants and products were continuously measured; applied voltage was set using a high-voltage power supply; and molar composition of products for each case was analyzed using gas chromatography. Results showed that CO2 dissociation rate, energy conversion efficiency and CO2-to-CO conversion yield increased with applied voltage. Moreover, CO2 dissociation rate and conversion yield decreased while energy conversion efficiency increased with increasing flow rate