Infrared spectroscopy of zinc oxide and magnesium nanostructures

Impurities in ZnO nanoparticles andMg nanorods were investigated. ZnO nanopar-ticles were prepared by a reaction of zinc acetate and sodium hydrogen carbonate. Thepresence and source of CO2 impurities in ZnO nanoparticles were studied by infrared(IR) spectroscopy. Isotopic substitution was used to verify the vibrational frequencyassignment. Isochronal annealing experiments were performed to study the formationand stability of molecular impurities. The results indicate that the molecules are muchmore stable than CO2 adsorbed on bulk ZnO surfaces. IR reflectance spectra of as-grown and hydrogen-annealed ZnO nanoparticles were measured at near-normal incidence. The as-grown particles were semi-insulating and showed reflectance spectra characteristic of insulating ionic crystals. Samples annealed in hydrogen showed a significant increase in electrical conductivity and free-carrier ab-sorption. A difference was observed in the reststrahlen line shape of the conductive sample compared to that of the as-grown sample. The effective medium approximation was applied to model the reflectance and absorption spectra. The agreement between the experimental results and the model suggests that the nanoparticles have inhomogeneous carrier concentrations. Exposure to oxygen for several hours led to a significant decrease in carrier concentration, possibly due to the adsorption of negative oxygen molecules on the nanoparticle surfaces. Cu doped ZnO nanoparticles were prepared by using a zinc acetate/copper acetate precursor. The electronic transitions of Cu2+ ions were observed in the IR absorption spectrum at low temperatures. The high resistivity property of ZnO:Cu nanoparticles was observed. Magnesium hydroxide thin layers were formed by a chemical reaction between magnesium nanorods and water. IR spectroscopy showed hydroxide (OH) vibrational modes. The assignment was verified by reactions with heavy water which produced the expected OD vibrational frequency. A Fano interference was detected for hydroxide layers formed on metallic magnesium. For hydroxide layers on insulating magnesium hydride, however, the line shape was symmetric and no Fano resonance was observed. The results show that the hydroxide layer is thin such that the vibrational motion couples to the free electron continuum of the magnesium metal

Modelling of Sunshine Duration for Peninsular Malaysia

Knowledge of solar radiation at any area is important for designing solar energy conversion systems, and is also useful for ecophysiological studies. In the present study, we have analysed the daily sunshine duration records for Peninsular Malaysia and apply them in solar radiation modelling. Firstly, we fitted Angstrom type equation to solar radiation and sunshine duration, to deter mine the relation between them. We have found that the seasonal variations of the regression parameters, are different for even two nearby locations. Variation of solar radiation within a small area are also noticable. Secondly, we have studied on the probability distribution nature of daily relative sunshine duration. Daily relative sunshine duration data are fitted to three models. Parameters of the models are estimated only from the monthly mean. Kolmogorov-Smirnov test is applied to determine the goodness of fit. We have found that the four stations can model led by two distributions. Data are also fitted to well known beta distribution model. The effect of variance is also presented. Finally, time series analysis of daily relative sunshine duration data are presented in chapter 4. Using gaussian mapping technique, nonstationary and non-normal distribution nature of the sunshine can be transformed into stationary and normal distribution. The autocorrelation function and partial autocorrelation function show the characteristics of autoregressive process. Results from the Box-Pierce and Ljung-Box statistics indicate that the first order autoregressive model is not suitable, while the second order autoregressive model gives satisfactory results. The relative sunshine duration of any day is dependent on the previous two days

Grain size and texture of Cu2ZnSnS4 thin films synthesized by co-sputtering binary sulfides and annealing: effects of processing conditions and sodium

ManuscriptWe investigate the synthesis of kesterite Cu2ZnSnS4 (CZTS) polycrystalline thin films using cosputtering from binary sulfide targets followed by annealing in sulfur vapor at 500 ?C to 650 ?C. The films are the kesterite CZTS phase as indicated by x-ray diffraction, Raman scattering, and optical absorption measurements. The films exhibit (112) fiber texture and preferred low-angle and ?3 grain boundary populations which have been demonstrated to reduce recombination in Cu(In,Ga)Se2 and CdTe films. The grain growth kinetics are investigated as functions of temperature and the addition of Na. Significantly, lateral grain sizes above 1 ?m are demonstrated for samples grown on Na-free glass, demonstrating the feasibility for CZTS growth on substrates other than soda lime glass

Update on Edoxaban for the Prevention and Treatment of Thromboembolism: Clinical Applications Based on Current Evidence

Vitamin K antagonists (VKA) and heparins have been utilized for the prevention and treatment of thromboembolism (arterial and venous) for decades. Targeting and inhibiting specific coagulation factors have led to new discoveries in the pharmacotherapy of thromboembolism management. These targeted anticoagulants are known as direct oral anticoagulants (DOACs). Two pharmacologically distinct classes of targeted agents are dabigatran etexilate (Direct Thrombin Inhibitor (DTI)) and rivaroxaban, apixaban, and edoxaban (direct oral factor Xa inhibitors (OFXaIs)). Emerging evidence from the clinical trials has shown that DOACs are noninferior to VKA or low-molecular-weight heparins in the prevention and treatment of thromboembolism. This review examines the role of edoxaban, a recently approved OFXaI, in the prevention and treatment of thromboembolism based on the available published literature. The management of edoxaban in the perioperative setting, reversibility in bleeding cases, its role in cancer patients, the relevance of drug-drug interactions, patient satisfaction, financial impacts, and patient education will be discussed

Analysis of residuals in daily solar radiation time series

The Box-Jenkins approach is applied to daily solar radiation data from four different locations in Malaysia. The deterministic annual component is obtained by Fourier analysis. The stochastic component of the time series is fitted to three models, ARMA (1,0), ARMA (2,0) and ARMA (1,1). Random shocks from these models are tested by Box-Pierce statistic and Ljung-Box for whiteness of residuals. Skewness and kurtosis coefficients are tested for normality

Poverty among households living in slum area of Hlaing Tharyar Township, Yangon City, Myanmar

Background: Slums can be regarded as physical manifestations of urban poverty. Although the world has made dramatic improvement in reducing poverty since 1990, poverty still persists at an unacceptable level. Although current situations highlights the importance of slum areas to be given priority in poverty alleviation, there are limited data on poverty level among people living in urban slums of Myanmar.Methods: A cross-sectional study was conducted among households living in slum areas of Hlaing Tharyar Township, Yangon City, Myanmar during 2016. Multi-staged systematic random sampling and face-to-face interview were applied in selecting the samples and collecting the data, respectively. The new global poverty line (1.9 USD per person per day) was used as a threshold in determining the poverty. Chi-squared test and multivariate logistic regression analysis were utilized in data analysis.Results: Altogether 254 participants were recruited after getting informed consent. The occurrence of poverty among households was 54.3% (95% CI: 48.2%, 60.5%). Head counts of poverty among study population was 58.8%. The education status of household’s head, size of household and the presence of less than 15 years old children in the household were detected as significant determinants of being poor household.Conclusions: Poverty among households living in slum area of Hlaing Tharyar Township, Yangon City was high. Measures to alleviate poverty in urban slums should be intensified. Education level of household’s heads should be improved. Family planning or birth spacing programme should also be strengthened, especially in urban slums.

Conceptual design of a hybrid thermal and photovoltaic receiver of an FMDF collector

The optical characteristic of a Fixed Mirror Distributed Focus (FMDF) solar collector is used as a basis for the design of an hybrid thermal and photovoltaic (PV) receiver. The result provides another variation in energy conversion that an FMDF solar collector can conveniently perform

Investigation of Japanese Encephalitis Virus Infection in Bogalay Township, Myanmar in 1999

An investigation was in Nyi-naung-wa village, Bogalay township for Japanese encephalitis (JE) virus infection and the possibility of a JE outbreak. JE virus antibody was determined among the pigs and the people living near the pig farms in that village and at an adjacent village as a control. The known JE virus vector Culex mosquito species were also identified in both villages. Haemagglutination inhibition (HAI) methods were used for the detectioon of JE and dengue antibodies. Homotypic or monotypic JE antibodies were detected in 33% of the pigs tested. No homotypic nor monotypic JE antibodis was detected among the villagers. Although there was no JE virus infection among the people, because of the presence of JE virus infection among the pigs and the presence of Culex mosquito vector in that area, the possibility of a JE outbreak in humans in that area, if the number of pig breeding per household increase and the mosquito density become higher is discussed