Docosahexaenoic acid production from crude glycerol by <Emphasis Type="Italic">Schizochytrium limacinum</Emphasis> SR21

In our search for a substitute energy source, microalgal biodiesel has presented itself as a potential candidate. However, the development of biodiesel results in the overproduction of crude glycerol, which can cause undesirable environmental issues. The environmental harm can be minimized by converting crude glycerol into value-added products. One solution involves using a microalga Schizochytrium limacinum SR21 to convert crude glycerol into docosahexaenoic acid (DHA). DHA is an essential fatty acid, necessary for developing brain functions in infants and maintaining healthy brain activity in adults. In our study, the highest DHA productivity of 233.73 mg/g biomass was obtained using 3 % crude glycerol in Medium 2 at 20 °C under mixo/heterotrophic cultivation.     

Crystal Phase and Phonon Densities of States of β'-SiAION Ceramics, Si6-zAlzOzN8-z (0 ≤z≤ 4)

The crystal structure and phonon densities of states (DOS) of β-SiAlON ceramics, Si₆_ _z Al _z O _z N_8-z (0 < z < 4), prepared by a novel slipcast method, are studied by neutron-scattering techniques. The samples with z < 4 form a single-phase solid solution of Si-Al-O-N isostructural to β-Si₃N₄ (space group P 6 ₃/m). A consistent preferential occupation of the 2c sites by oxygen atoms and the 6 h sites by nitrogen atoms exists within this structure. The phonon DOS of β'-SiAlON displays phonon bands at ∼50 and 115 meV. These features are considerably broader than the corresponding ones in β-Si₃N₄ powder.     

Investigation of phase behavior during melt processing of novel inorganic‐organic polymer hybrid material

The phase behavior of novel, binary organic‐inorganic hybrids consisting of an ultra‐low T_g tin‐based phosphate glass (Pglass) and polystyrene (PS) was investigated. Dynamic mechanical analysis (DMA) revealed that the glass transition peaks of the PS changed slightly with Pglass volume fraction, leading to a broad peak at the phase inversion point. The phase inversion and degree of phase continuity of the hybrid were studied through solvent extraction, optical/scanning electron microscopy, and dynamic rheology. The Jordhamo and Utracki viscosity ratio models provided reliable estimates of the inversion point. Torque rheometry revealed a trend toward linear additivity within the temperature range 200°C–230°C. Small‐angle neutron scattering experiments gave further evidence of the hybrid phase incompatibility. The results of this study point to a promising new class of blend materials with the potential to present a unique combination of properties impossible to achieve with classical polymer blends. Polym. Eng. Sci. 44:1692–1701, 2004. © 2004 Society of Plastics Engineers.     

Proportionally fair load balancing with statistical quality of service provisioning for aerial base stations

Aerial base stations (ABSs) seem promising to enhance the coverage and capacity of fifth-generation and upcoming networks. With the flexible mobility of ABSs, they can be positioned in air to maximize the number of users served with a guaranteed quality of service (QoS). However, ABSs may be overloaded or underutilized given inefficient placement, and user association has not been well addressed. Hence, we propose a three-dimensional ABS placement scheme with a delay-QoS-driven user association to balance loading among ABSs. First, a load balancing utility function is designed based on proportional fairness. Then, an optimization problem for joint ABS placement and user association is formulated to maximize the utility function subject to statistical delay QoS requirements and ABS collision avoidance constraints. To solve this problem, we introduce an efficient modified gray wolf optimizer for ABS placement with a greedy user association strategy. Simulation results demonstrate that the proposed scheme outperforms baselines in terms of load balancing and delay QoS provisioning.     

A Flexi-PEGDA Upconversion Implant for Wireless Brain Photodynamic Therapy

Near-infrared (NIR) activatable upconversion nanoparticles (UCNPs) enable wireless-based phototherapies by converting deep-tissue-penetrating NIR to visible light. UCNPs are therefore ideal as wireless transducers for photodynamic therapy (PDT) of deep-sited tumors. However, the retention of unsequestered UCNPs in tissue with minimal options for removal limits their clinical translation. To address this shortcoming, biocompatible UCNPs implants are developed to deliver upconversion photonic properties in a flexible, optical guide design. To enhance its translatability, the UCNPs implant is constructed with an FDA-approved poly(ethylene glycol) diacrylate (PEGDA) core clad with fluorinated ethylene propylene (FEP). The emission spectrum of the UCNPs implant can be tuned to overlap with the absorption spectra of the clinically relevant photosensitizer, 5-aminolevulinic acid (5-ALA). The UCNPs implant can wirelessly transmit upconverted visible light till 8 cm in length and in a bendable manner even when implanted underneath the skin or scalp. With this system, it is demonstrated that NIR-based chronic PDT is achievable in an untethered and noninvasive manner in a mouse xenograft glioblastoma multiforme (GBM) model. It is postulated that such encapsulated UCNPs implants represent a translational shift for wireless deep-tissue phototherapy by enabling sequestration of UCNPs without compromising wireless deep-tissue light delivery.     

Colour degradation of acidified vegetable juice

Mixed vegetable juice was acidified to a pH below 4 and subjected to pasteurization regimes between 80 and 100 °C. Hunter colour scale values (L, a and b) of the pasteurized samples were analysed to determine the kinetics of green and total colour degradation. The ‘a’ value was chosen as the physical parameter for green colour while ‘Lab’ represented the total colour. A concept, based on fractional conversion, was used for the determination of kinetic parameters. The results revealed that degradation of green and total colour of the acidified vegetable juice followed first‐order kinetics. Temperature dependency of the rate constants for both the green and the total colour could be described by the Arrhenius relationship. The activation energies of green and total colour degradation were 49.19 and 29.00 kJ mol^?1, respectively.     

Impact of Backup Power in Optimizing Deployment Cost of Hybrid Optical Wireless Broadband Access Network (HOWBAN) with Survivability

Wireless Personal Communications - The dependence on broadband to enhance the economy and environment sustainability is imposing immense urgency to provide ubiquitous wireless broadband access...     

Limonene transport and mechanical properties of EVOH and nylon 6,6 films as influenced by RH

The transport properties of d‐limonene through ethylene vinyl alcohol copolymers (EVOH) and nylon 6,6 films as functions of relative humidity (RH) and temperature were studied. Permeation properties of these polymers were strongly influenced by temperature and RH. Compared to the EVOH films, the nylon 6,6 film had much greater limonene permeability. Mechanical property studies indicated that both the tensile modulus and yield strength of the EVOH films decreased with an increase in RH. The polymer changed from being stiff and brittle at low RH to being soft and ductile at high RH. In addition, ethylene content and orientation were found to affect the transport and mechanical properties of limonene through EVOH polymers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1949–1957, 2001