Bioethanol production from micro-algae, Schizocytrium sp., using hydrothermal treatment and biological conversion

Hydrothermal fractionation for micro-algae, Schizocytrium sp., was investigated to separate sugars, lipids, and proteins. This fractionation process produced protein-rich solid cake and liquid hydrolysates, which contained oligomeric sugars and lipids. Oligomeric sugars and lipids were easily separated by liquid-liquid separation. Sugars in the separated hydrolyzate were determined to be mainly D-glucose and L-galactose. Fractionation conditions were optimized by response surface methodology (RSM). Optimal conditions were found to be 115.5 °C of reaction temperature, 46.7 min of reaction time, and 25% (w/w) of solid loading. The model predicted that maximum oligomeric sugar yield (based on untreated micro-algae weight), which can be recovered by hydrothermal fractionation at the optimum conditions, was 19.4 wt% (based on the total biomass weight). Experimental results were in agreement with the model prediction of 16.6 wt%. Production of bioethanol using micro-algae-induced glucan and E. coli KO11 was tested with SSF (simultaneous saccharification and fermentation), which resulted in 11.8 g-ethanol/l was produced from 25.7 g/l of glucose; i.e. the theoretical maximum ethanol yield based on glucan in hydrolyzate was 89.8%.     

Kinetics and thermodynamics of paclitaxel extraction from plant cell culture

We investigated the effect of temperature on the efficiency of paclitaxel extraction from biomass. In addition, kinetic and thermodynamic studies of this extraction process were performed. The concentration of extracted paclitaxel increased with increasing extraction temperature and extraction time. When the experimental data were applied to various kinetic models, the hyperbolic model (second-order model) was the most appropriate. The predictive model was developed to predict the concentration of extracted paclitaxel at different temperatures at a given time. The Gibbs free energy change was determined to be negative, while enthalpy change and entropy change were positive. These results indicate that this extraction process is spontaneous, endothermic, and irreversible.     

A new fluoride mediated synthesis of mesoporous silica and their usefulness in controlled delivery of duloxetine hydrochloride a serotonin re-uptake inhibitor

A new type of mesoporous silica nanoparticle (MSN) was synthesized in fluoride media via sol–gel technique using TritonX 100 and Tween-20. The surface area and pore volume of the MSN particles were modified by varying the concentration of Tween-20. The prepared MSN nanoparticles with large surface area and pore volume (T-2, T-3) were selected to accommodate the model drug duloxetine hydrochloride (DX) for evaluation of their drug-loading and release abilities. Calcined and DX loaded nanoparticles were characterized by Brunauer–Emmett–Teller technique (BET), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric (TG) analysis and UV-diffuse reflectance (UV-DRS). In vitro release studies proved that the particle displays an initial burst release followed by sustained release for up to 140 h. From the studies it is evident that the synthesized particle may be useful as a carrier for sustained release of active pharmaceutical ingredients (APIs).     

Hybrid film of chemically modified graphene and vapor-phase-polymerized PEDOT for electronic nose applications

A hybrid of graphene and conducting polymer holds great potential as the active materials for high performance chemical sensor application. In this work, a thin hybrid film of reduced graphene oxide (RG-O) and poly(3,4-ethylenedioxythiophene) (PEDOT) was fabricated by means of vapor phase polymerization and explored as active material for chemical sensors. The chemical sensors based on hybrid film of RG-O and PEDOT are capable of detecting electrical signals caused by the absorption of trace levels of different analyte vapors with high sensitivity, selectivity and fast response.     

Soft-, shape changing materials toward physicochemically powered actuators

A shape changing material (SCM) morphs its shape upon external stimulus, and it offers a design of complex 3-dimensional structures remotely, which can be potentially useful for biomedical tools, drug delivery, and soft robotics. To actuate such structures through a physicochemical stimulus, stimuli-responsive materials have been studied over the past few decades. Several SCMs have been reported by combining novel stimuli-responsive materials, micropatterning techniques and a unique actuation cue. In this review, we introduce a recent development in SCMs within the aspects of their materials and structures to describe how the materials can be designed and actuated on demand. Finally, we discuss the future direction and challenges for SCMs as physicochemically-powered actuators.     

Stall inception and warning in a single-stage transonic axial compressor with axial skewed slot casing treatment

Characteristic changes in the stall inception in a single-stage transonic axial compressor with an axial skewed slot casing treatment were investigated experimentally. A rotating stall occurred intermittently in a compressor with an axial skewed slot, whereas spike-type rotating stalls occurred in the case of smooth casing. The axial skewed slot suppressed stall cell growth and increased the operating range. A mild surge, the frequency of which is the Helmholtz frequency of the compressor system, occurred with the rotating stall. The irregularity in the pressure signals at the slot bottom increased decreasing flow rate. An autocorrelation-based stall warning method was applied to the measured pressure signals. Results estimate and warn against the stall margin in a compressor with an axial skewed slot.     

Quantitative biology of single neurons

The building blocks of complex biological systems are single cells. Fundamental insights gained from single-cell analysis promise to provide the framework for understanding normal biological systems development as well as the limits on systems/cellular ability to respond to disease. The interplay of cells to create functional systems is not well understood. Until recently, the study of single cells has concentrated primarily on morphological and physiological characterization. With the application of new highly sensitive molecular and genomic technologies, the quantitative biochemistry of single cells is now accessible.     

Joint Optimization of User Set Selection and Transmit Power Allocation for Orthogonal Random Beamforming in Multiuser MIMO Systems

When the number of users is finite, the performance improvement of the orthogonal random beamforming (ORBF) scheme is limited in high signal‐to‐noise ratio regions. In this paper, to improve the performance of the ORBF scheme, the user set and transmit power allocation are jointly determined to maximize sum rate under the total transmit power constraint. First, the transmit power allocation problem is expressed as a function of a given user set. Based on this expression, the optimal user set with the maximum sum rate is determined. The suboptimal procedure is also presented to reduce the computational complexity, which separates the user set selection procedure and transmit power allocation procedure.     

Electrically assisted stress relief annealing of automotive springs

Journal of Mechanical Science and Technology - In the present study, Electrically assisted (EA) stress relief annealing for automotive springs is experimentally investigated. A concept of EA stress...