High Efficiency CMOS Class E Power Amplifier Using 0.13 μm Technology-0

This paper presents the design of a 2.4-GHz CMOS Class E power amplifier (PA) for wireless applications in Silterra 0.13-μm CMOS technology. The Class E PA proposed in this paper is a single-stage PA in a cascode topology in order to minimize the device stress problem. All transistors are arranged in parallel to decrease on-resistance for high efficiency with on-chip input and output impedance matching. The simulation results indicate that the PA delivers 11.9 dBm output power and 53% power added efficiency (PAE) with 1.3-V power supply into a 50-Ω load. The chip layout is 0.27 mm2

Polystyrene Particles and Mammalian Cells Motion Behaviour on Different Surfaces

The stochastic motion behaviour of polystyrene particles and  teratocarcinoma cells on plain and functionalised surfaces is investigated and analysed. The solution of 1 x 106 particles/cells per ml concentration is pipetted into a reservoir and images are captured and analysed using an in-house written software. A theoretical model was used to predict the motion and compared to the experimental results. The conditions and limitations to allow particles and cells to move freely in stochastic motion on surface are discussed in this paper. PEG functionalisation of the glass surface was found to improve the particles and cells mobility, on average 26%. Analysis technique proposed in this paper demonstrates that size distribution of different cell line can be determined. The results are presented in light of the potential application of the observed motion on functionalised surfaces for lab-on-a-chip devices, especially for adherent biological cells applications

Potential of oil palm trunk starch as flocculant for contaminant of emerging compound removal

In this preliminary study, a natural flocculant is developed from an oil palm trunk. The flocculant further tested for its ability in turbidity and COD removal with additional of atrazine in wastewater and demineralised water matrix. At the optimum dosage of 20mg/L, the developed cationic OPT starch able to remove around 95% turbidity and 85% COD. In addition, the cationic OPT starch also show the ability to remove spiked atrazine from both water matrixes to the maximum range of 55-85%. In conclusion, the developed oil-palm based flocculant show great potential for real-world application with added cost-effective benefits

Methanogenic Biodegradation of iso-Alkanes by Indigenous Microbes from Two Different Oil Sands Tailings Ponds

iso-Alkanes, a major fraction of the solvents used in bitumen extraction from oil sand ores, are slow to biodegrade in anaerobic tailings ponds. We investigated methanogenic biodegradation of iso-alkane mixtures comprising either three (2-methylbutane, 2-methylpentane, 3-methylpentane) or five (2-methylbutane, 2-methylpentane, 2-methylhexane, 2-methylheptane, 2-methyloctane) iso-alkanes representing paraffinic and naphtha solvents, respectively. Mature fine tailings (MFT) collected from two tailings ponds, having different residual solvents (paraffinic solvent in Canadian Natural Upgrading Limited (CNUL) and naphtha in Canadian Natural Resources Limited (CNRL)), were amended separately with the two mixtures and incubated in microcosms for ~1600 d. The indigenous microbes in CNUL MFT produced methane from the three-iso-alkane mixture after a lag of ~200 d, completely depleting 2-methylpentane while partially depleting 2-methylbutane and 3-methylpentane. CNRL MFT exhibited a similar degradation pattern for the three iso-alkanes after a lag phase of ~700 d, but required 1200 d before beginning to produce methane from the five-iso-alkane mixture, preferentially depleting components in the order of decreasing carbon chain length. Peptococcaceae members were key iso-alkane-degraders in both CNUL and CNRL MFT but were associated with different archaeal partners. Co-dominance of acetoclastic (Methanosaeta) and hydrogenotrophic (Methanolinea and Methanoregula) methanogens was observed in CNUL MFT during biodegradation of three-iso-alkanes whereas CNRL MFT was enriched in Methanoregula during biodegradation of three-iso-alkanes and in Methanosaeta with five-iso-alkanes. This study highlights the different responses of indigenous methanogenic microbial communities in different oil sands tailings ponds to iso-alkanes

Stochastic Motion of Teratocarcinoma Cells on PEG Functionalised Surfaces

AbstractThe stochastic motion behaviour of teratocarcinoma cells on PEG functionalised surfaces is investigated and analysed. The solution of 1 x 106 cells per ml concentration is pipetted into a reservoir and images are captured and analysed using an in-house written software. A theoretical model was used to predict the motion and compared to the experimental results. The conditions and limitations to allow teratocarcinoma cells (naturally adherent cells) to move freely in stochastic motion on surface are discussed in this paper. PEG functionalisation of the glass surface was found to improve the cells mobility, on average 26%. Analysis technique proposed in this paper demonstrates that size distribution of different cell lines can be determined. The results are presented in light of the potential application of the observed motion on functionalised surfaces for lab-on-a-chip devices, especially for adherent biological cells applications

Optical propulsion of mammalian eukaryotic cells on an integrated channel waveguide

The optical propulsion of mammalian eukaryotic cells along the surface of an integrated channel waveguide is demonstrated. 10µm diameter polymethylmethacrylate (PMMA) spherical particles and similarly sized mammalian eukaryotic cells in aqueous medium are deposited in a reservoir over a caesium ion-exchanged channel waveguide. Light from a fibre laser at 1064nm was coupled into the waveguide, causing the polymer particles or cells to be propelled along the waveguide at a velocity which is dependent upon the laser power. A theoretical model was used to predict the propulsion velocity as a function of the refractive index of the particle. The experimental results obtained for the PMMA particles and the mammalian cells show that for input powers greater than 50mW the propulsion velocity is approximately that obtained by the theoretical model. For input powers of less than ~50mW neither particles nor cells were propelled; this is considered to be a result of surface forces (which are not considered in the theoretical model). The results are discussed in light of the potential application of optical channel waveguides for bioanalytical applications, namely in the identification and sorting of mammalian cells from mixed populations without the need for fluorescence or antibody labels

Single Brillouin frequency shifted S-band multi-wavelength Brillouin-Raman fiber laser utilizing fiber Bragg grating and Raman amplifier in ring cavity

Tento dokument je zaměřen na simulaci a analýzu S-band multi-vlnových délek výkonného Ramanova laseru Brillouine s využitím vláken Bragg a Ramanového zesilovače v kruhové dutině. Raman zesilovače se používají pro zesílení signálu průměrného výkonu modelu.This paper is focusing on simulation and analyzing of S-band multi-wavelength Brillouine Raman fiber laser performance utilizing fiber Bragg grating and Raman amplifier in ring cavity. Raman amplifier average power model is employed for signal amplificatio

Long-Term Incubation Reveals Methanogenic Biodegradation of C₅ and C₆ <i>iso</i>-Alkanes in Oil Sands Tailings

<i>iso</i>-Alkanes are major components of petroleum and have been considered recalcitrant to biodegradation under methanogenic conditions. However, indigenous microbes in oil sands tailings ponds exposed to solvents rich in 2-methylbutane, 2-methylpentane, 3-methylpentane, <i>n</i>-pentane, and <i>n</i>-hexane produce methane in situ. We incubated defined mixtures of <i>iso-</i> or <i>n-</i>alkanes with mature fine tailings from two tailings ponds of different ages historically exposed to different solvents: one, ∼10 years old, receiving C₅–C₆ paraffins and the other, ∼35 years old, receiving naphtha. A lengthy incubation (>6 years) revealed <i>iso-</i>alkane biodegradation after lag phases of 900–1800 and ∼280 days, respectively, before the onset of methanogenesis, although lag phases were shorter with <i>n</i>-alkanes (∼650–1675 and ∼170 days, respectively). 2-Methylpentane and both <i>n</i>-alkanes were completely depleted during ∼2400 days of incubation, whereas 2-methylbutane and 3-methylpentane were partially depleted only during active degradation of 2-methylpentane, suggesting co-metabolism. In both cases, pyrotag sequencing of 16S rRNA genes showed codominance of Peptococcaceae with acetoclastic (Methanosaeta) and hydrogenotrophic (Methanoregula and Methanolinea) methanogens. These observations are important for predicting long-term greenhouse-gas emissions from oil sands tailings ponds and extend the known range of hydrocarbons susceptible to methanogenic biodegradation in petroleum-impacted anaerobic environments

Relationship between education and cognitive performance among healthy Malay adults

Higher level of education is associated with better cognitive performance and lower risk of developing dementia. However, the effect of education on cognitive performance varies across different cognitive domains and in different populations. The aim of this study was to determine the relationship between education and performance of different cognitive domains among healthy Malay adults. A total of 53 individuals aged 29 to 77 years participated in a battery of neurophysiological tests consisting of Mini-Mental State Examination, Montreal Cognitive Assessment, digit span, visual reproduction and digit symbol speed test (DSST). Blood test was performed for each participant to obtain their biochemical profile. Educational level was divided into level 1 (PMR), level 2 (SPM), level 3 (STPM), level 4 (Diploma) and level 5 (Degree). Simple linear regression indicated that years of education was positively associated with scores of delayed visual reproduction (b=1.348, p=0.002) and DSST (b=3.257, p=0.012). However, scores of all the tests were not significantly different among different levels of education after controlling for age, gender and blood test profile by ANCOVA. Multiple linear regression analysis showed that MMSE score was associated with red cell distribution width (b=-0.628, p=0.005), age (b=-0.119, p<0.001) and there was interaction between high density lipoprotein (HDL) with age (b=0.047, p<001). MoCA score was associated with age (b=-0.121, p<0.001), gender (male compared to female, b=1.870, p=0.020) and HDL (b=1.681, p=0.047). Age was associated with backward digit span (b=-0098, p<0.001) and immediate visual reproduction (b=-0.348, p<0.001), resp. Delayed visual reproduction was associated with age (b=-0.323, p<0.001) and potassium level (b=-4.471, p=0.016). DSST was associated with age (b=-0.911, p<0.001) and alanine aminotransferase (b=-0.754, p=0.002). The lack of association between educational level and cognitive performance after adjusting for confounders in this study maybe due to multiple factors influencing cognitive performance and further studies with a larger sample size are needed to further identify the factors involved