Extraction of mangiferin from Mahkota Dewa (Phaleria macrocarpa) using subcritical water

A pharmacological active component, mangiferin, was extracted from Mahkota Dewa using subcritical water extraction. The subcritical water extractions were carried out at temperatures ranging 323–423 K, pressures ranging 0.7–4.0 MPa, and extraction times ranging 1–7 h. Extraction yield of mangiferin was measured using high-performance liquid chromatography (HPLC). The extraction yield was strongly dependent on the temperature while weakly dependent on the extraction pressure. As the extraction temperature increased, the extraction mangiferin yield increased, possibly resulting from the decrease in polarity of subcritical water at higher temperature. At an optimal extraction condition of 373 K, 4.0 MPa and extraction time of 5 h, the extraction yield of mangiferin was 21.7 mg/g. This value was close to the extraction yield with methanol (25.0 mg/g) and higher than those with water (18.6 mg/g) or ethanol (13.2 mg/g) at their boiling points.     

Development of a Simple,Rapid Multiplex PCR Method Using the 16S rRNA Gene to Determine the Country of Origin of Brackish Water Bivalve <Emphasis Type="Italic">Corbicula japonica</Emphasis>

In this study, a multiplex PCR detection method was developed to identify the country of origin of Corbicula japonica (clams), a commercially important bivalve in Asia. Specific primer sets that have a single nucleotide mismatch at the 3′ terminus were designed after sequencing the mitochondrial 16S rRNA gene of clams identified as C. japonica originating from Korea, China, and Japan. Using this method, each origin was clearly identified based on the PCR products: three bands for Korean C. japonica (100, 283, and 384 bp), one band for Chinese C. japonica (384 bp), and two bands for Japanese C. japonica (384 and 100 bp). These results indicate that the 16S rRNA gene, which is usually used to identify species, can distinguish the country of origin within C. japonica. Our multiplex PCR assay should be a useful tool for the fair trade of the species.     

The Effect of CeO2 Antireflection Layer on the Optical Properties of Thermochromic VO2 Film for Smart Window System

CeO₂-VO₂ bilayer structure was fabricated to investigate the effect of depositing CeO₂ film on the optical properties of VO₂ film for smart window application. CeO₂ was employed as an antireflection (AR) layer material of VO₂ film because of its advantages which include high transparency in the visible-near infrared range and high refractive index. All the films were deposited on soda-lime glass substrate by pulsed laser deposition method. Optical calculations were carried out using transfer-matrix method for the purpose of designing CeO₂-VO₂ bilayer structure with enhanced integrated luminous transmittance (T _lum) and switching efficiency (ΔT _sol). The optical constants of VO₂ and CeO₂ films needed for the optical calculation were measured by spectroscopic ellipsometer. The curve of T _lum the shape of which depends on the thickness of CeO₂ layer, was calculated in each VO₂ sample, which showed two maxima. The samples were divided into two groups; one for the highest enhancement of T _lum and the other for balanced enhancement between T _lum and ΔT _sol. The sample with the structure of ~60 nm CeO₂ AR layer on 39-nm thick VO₂ film showed large increase of T _lum (~27%) with ΔT _sol of ~5%, which is the largest increase in T _lum reported so far. Two samples in the other group showed the balanced enhancement in T _lum (~57, ~50%) and ΔT _sol (~9, ~10.5%). The effect of CeO₂ AR layer on the optical properties of VO₂ film was confirmed with the optical calculation and the experimental results. CeO₂-VO₂ bilayer structure showed notable improvement of optical properties compared to the single VO₂ film, indicating that CeO₂ layer can be effectively used as the antireflection layer while working as a protective layer that can prevent the oxidation of VO₂ layer as well.     

Highly-efficient single-cell capture in microfluidic array chips using differential hydrodynamic guiding structures

This paper presents a highly efficient single cell capture scheme using hydrodynamic guiding structures in a microwell array. The implemented structure has a capturing efficiency of >80%, and has a capacity to place individual cells into separated microwells, allowing for the time-lapse monitoring on single cell behavior. Feasibility was tested by injecting microbeads (15 μm in diameter) and prostate cancer PC3 cells in an 8×8 microwell array chip and >80% of the microwells were occupied by single ones. Using the chips, the number of cells required for cell assays can be dramatically reduced and this will facilitate overcoming a huddle of assays with scarce supply of cells.     

A study on driver’s workload of telematics using a driving simulator: A comparison among information modalities

Recently, diffusion of telematics services and an explosive increase of in-vehicle display devices, such as Car Navigation Systems (CNSs), are becoming the new causes of traffic accidents. This is due to ‘inattention’ caused by an increase in the driver’s mental workload while he/she is driving. This situation has lead many countries to consider controlling the use of in-vehicle devices while driving through legislation. This research studies the effect of voice or display information systems on drivers through the Driver Eye Movement Analysis and the measurement of response ability. The experiment is carried out in a driving simulator and the results are presented through the comparative analysis of the driver’s visual field via the gaze tracking device and the average of correct answer rates for arithmetic problems.     

Evaluation of pre‐heating and extraction solvents in antioxidant and antimicrobial activities of garlic,and their application in fresh pork patties

The objectives of this study were to screen the optimum conditions for antioxidant and antimicrobial activities of garlic as affected by pre‐heating and different extraction solvents, and to evaluate the antioxidant and antimicrobial effects of these extracts in ground meat during refrigerated storage. Methanol extracted garlic had a greater total phenolic content, 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH)‐radical scavenging activity and reducing power than water extracted one (P < 0.05), whereas the latter had a greater yield and iron chelating ability than the former (P < 0.05). Moreover, water extract from fresh garlic (WEFG) and methanol extract from heated garlic (MEHG) produced an inhibition zone against Escherichia coli O157:H7 and Listeria monocytogenes. The addition of garlic extracts (WEFG, MEHG and their combinations WEFMEHG)) to pork patties decreased the pH, hunter a values (redness), thiobarbituric acid substances values and the number of total plate count and Enterobacteriaceae (P < 0.05), while the hunter b values (yellowness) increased (P < 0.05). Results of this study indicated that the use of the garlic extracts was able to control lipid oxidation and microbial growth in pork patties.     

Measurement of nonlinear mechanical properties of PDMS elastomer

This paper presents the measurement of the nonlinear mechanical properties of polydimethylsiloxane (PDMS) elastomer based on the mixing ratio of base polymer to curing agent. Strip-type PDMS samples with different mixing ratios were prepared using a simple coating, curing, and cutting process. A cyclic uniaxial tension test with a fixed magnitude of applied strain and a single-pull-to-failure tension test were performed with a micro-tensile tester at room temperature.Our new finding is that when the PDMS is mixed with excessive curing agent, stress softening occurs and residual strain exists in cyclic tension tests when the magnitude of the applied strain increases. For the PDMS-05 samples, in which the mixing ratio of base polymer to curing agent was 5 to 1, there were large differences in the stresses for the same strain level under loading and unloading during the first cycle with a 100% fixed strain amplitude, but the softening effect of the stress in the PDMS dropped rapidly starting from the second cycle.Nonlinear mechanical Neo-Hookean, third-order Mooney, and second-order Ogden models of three different PDMS films were computed from the stress-strain data. The results showed that all models were preferable for the small strain region of PDMS compared with other models. In the nonlinear, large strain region, only the second-order Ogden model properly described the mechanical behavior of the PDMS, while the Neo-Hookean and third-order Mooney-Rivlin models were too stiff or flexible in the measurement range. The bulk modulus of PDMS increased with the amount of curing agent in it. Therefore, the second-order Ogden model is preferable for analyzing the PDMS structure over the entire measurement range. This could provide reasonable mechanical models of PDMS for rapid computational prototyping and for designing active and passive components from PDMS.     

Mixing characteristics of pulsed air-assist liquid jet into an internal subsonic cross-flow

Penetration depth,spray dispersion angle,droplet sizes in breakup processes and atomization processes are very important parameters in combustor of air-breathing engine.These processes will enhance air/fuel mixing inside the combustor.Experimental results from the pulsed air-assist liquid jet injected into a cross-flow are investigated.And experiments were conducted to a range of cross-flow velocities from 42～136 m/s.Air is injected with 0～300kPa,with air-assist pulsation frequency of 0～20Hz.Pulsation frequency was modulated by solenoid valve.Phase Doppler Particle Analyzer(PDPA) was utilized to quantitatively measuring droplet characteristics.High-speed CCD camera was used to obtain injected spray structure.Pulsed air-assist liquid jet will offer rapid mixing and good liquid jet penetration.Air-assist makes a very fine droplet which generated mist-like spray.Pulsed air-assist liquid jet will introduce additional supplementary turbulent mixing and control of penetration depth into a cross-flow field.The results show that pulsation frequency has an effect on penetration,transverse velocities and droplet sizes.The experimental data generated in these studies are used for a development of active control strategies to optimize the liquid jet penetration in subsonic cross-flow conditions and predict combustion low frequency instability.     

Reprocessing of spent nuclear waste using ionic liquids

Nuclear power has once again attracted from all over the world due to many factors including the rise in oil process and environmental concerns on greenhouse gas emission resulting in global warming. However, spent fuel from nuclear power reactors is an enormous problem both from radiation hazard and economical point of view. Therefore, this review presents an overview of application of ionic liquids (ILs) in spent fuel reprocessing, particularly in the extraction of high-level radioactive aqueous waste from the processing of nuclear fuel.