Effect of municipal liquid waste on corrosion susceptibility of galvanized steel pipe

This investigation studied the effect of municipal liquid waste discharged into the environment within Kano municipal area on the corrosion susceptibility of galvanized steel pipe burial underground. Six stagnant and six moving municipal liquid waste samples were used for the investigation. The corrosion rate of the galvanized steel pipe was measured using the gravimetric technique. The results obtained from weight loss measurement shows a serious corrosion effect of municipal liquid waste on the galvanized steel pipe. The overall corrosion rates are much higher in the stagnant and moving liquid waste samples collected within the core city than the liquid waste samples collected outside the city, but become low with the formation of passive films on galvanized steel surface after 2500 hours. Therefore, this investigation revealed that the galvanized steel pipes used to supply the city with pipe borne water are at high risk of supplying contaminated water due to some leaking pipes. Key words: Liquid waste, galvanized steel, weight loss, ravimetric, corrosion, leakin

Short-term denitrification in the metalimnion of a eutrophic reservoir

Denitrification in metalimnetic water was examined under different conditions to determine how of addition of nitrate (NO3-) and particulate carbon (PC), aeration, and concentrations of nitrate affect denitrification. In the first experiment, water samples from a metalimnion were treated with different combinations of NO3- and PC to find out how addition of NO3- and PC changes denitrification occurring in a metalimnion. The treatments included 1) control, 2) samples amended with 1 mg NO3− - N/L, 3) samples amended with both NO3− (1 mg NO3− - N/L) and PC (5.7 mg C/L), and 4) samples amended with 5.7 mg C/L. Changes in excess N2-N concentration for 10 days were measured using membrane inlet mass spectrometry (MIMS). In the second experiment, the same treatments were used to evaluate the effect of aeration. Besides excess N2-N concentrations, O2 concentrations were measured for 16 days. The third experiment examined how different initial concentrations of NO3- influenced denitrification, and changes in the samples with the four different concentrations of 1) control with 0 mg NO3− - N/L, 2) 1.0 mg NO3− - N/L, 3) 2.5 mg NO3− - N/L, and 4) 5.0 mg NO3− - N/L were measured using MIMS for 42 days. The first experiment indicated that all samples in this experiment had completed denitrification before this experiment, and denitrification occurred only in the samples added with NO3−. Aeration event in the second experiment resulted in low initial excess N2-N concentrations, and excess N2-N concentrations increased most in the samples containing both PC and NO3− and second most in PC amended samples. Excess N2-N concentrations did not increase in other two treatments, indicating the effect of PC on creating anoxic conditions for denitrification. Differences in initial NO3− concentrations did not result in differences in denitrification

Migration of African-trained physicians abroad : a case study of Saskatchewan, Canada

Several factors inform health professionals’ decisions to migrate from developing to developed countries to practice their profession. This study explores the “Push” and “Pull” factors that informed African-trained physicians’ decisions to migrate to the province of Saskatchewan, how well they integrated into their new working environments upon arrival and how that might contribute to future migration and retention in Saskatchewan. Based on questionnaire surveys and face-to-face interviews, this study identified differences in the relative importance of precipitating factors for physicans’ from South, North and “Other” African nations. Although the majority of African-trained physicians’ for the study indicated that profession-related push factors were the precipitating factors for their migration, a smaller number did not cite these as important. Most respondents for the study integrated well into the health care system and have remained at their current location of practice because of the support they received from colleagues at their work places

閉塞性細気管支炎患者における中枢気管支拡張の意義

京都大学新制・課程博士博士(医学)甲第24501号医博第4943号新制||医||1064(附属図書館)京都大学大学院医学研究科医学専攻(主査)教授 永井 洋士, 教授 大鶴 繁, 教授 江木 盛時学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDFA

Angular Trispectrum of CMB Temperature Anisotropy from Primordial Non-Gaussianity with the Full Radiation Transfer Function

We calculate the cosmic microwave background (CMB) angular trispectrum, spherical harmonic transform of the four-point correlation function, from primordial non-Gaussianity in primordial curvature perturbations characterized by a constant non-linear coupling parameter, $f_{\rm NL}$. We fully take into account the effect of the radiation transfer function, and thus provide the most accurate estimate of the signal-to-noise ratio of the angular trispectrum of CMB temperature anisotropy. We find that the predicted signal-to-noise ratio of the trispectrum summed up to a given $l$ is approximately a power-law, $(S/N)(<l)\sim 2.2\times 10^{-9}f^2_{\rm NL}l^2$, up to the maximum multipole that we have reached in our numerical calculation, $l=1200$, assuming that the error is dominated by cosmic variance. Our results indicate that the signal-to-noise ratio of the temperature trispectrum exceeds that of the bispectrum at the critical multipole, $l_c \sim 1500~(50/|f_{\rm NL}|)$. Therefore, the trispectrum of the Planck data is more sensitive to primordial non-Gaussianity than the bispectrum for $|f_{\rm NL}|\gtrsim 50$. We also report the predicted constraints on the amplitude of trispectrum, which may be useful for other non-Gaussian models such as curvaton models.Comment: 6 pages, 2 figures, version to be published in PR

New liquid crystals in the series of 1, 3, 5-triazine compounds containing azobenzene at the peripheral arms

Novel liquid crystal materials whose molecular structures consist of disc-like 1,3,5-triazine unit as a central core and three rod-like azobenzenes as the peripheral arms unit has been prepared and characterized by spectroscopic methods, and X-ray diffraction. The Series of compounds were prepared by nucleophilic addition of the primary amino nucleophile to 1,3,5-triazine electrophilic ring via alkyl spacers in presence of potassium carbonate as hydrochloride acceptor. Differencial scanning calorimetry (DSC), polarizing optical microscopy and x-ray diffraction confirmed Smectic mesophase textures of the materials. Increase in the polymethylene spacer length influence the thermal and phase stability of the compounds studied

Optimization of mechanical properties of chitosan/phenol formaldehyde composite

The Frechet distribution which has a scale and shape parameters, has been found to have wide application in modelling extreme events such as radioactive emission, flood, rainfall, seismic analysis, wind speed, etc. In this research paper, the Bayesian analysis of scale parameter of Frechet distribution was considered. It is necessary to know the best combination of prior distribution and loss function for the parameter estimation. Posterior distribution was derived by uniform and Jeffrey’s prior under the square error, Precautionary, Quadratic and Weighted balance loss function. Bayes estimation and their corresponding risk was obtained by the above stated priors and loss function. Monte Carlo simulations was conducted to compare the performance of the estimators. It is evident that weighted balance loss function when used with uniform prior provides the least posterior risk.Keywords: Frechet Distribution, Non-Informative Prior, Bayesian Estimation, Loss Functions, Monte Carlo Simulation

Constraining Cosmological Parameters by the Cosmic Inversion Method

We investigate the question of how tightly we can constrain the cosmological parameters by using the ``cosmic inversion'' method in which we directly reconstruct the power spectrum of primordial curvature perturbations, $P(k)$, from the temperature and polarization spectra of the cosmic microwave background (CMB). In a previous paper, we suggested that it may be possible to constrain the cosmological parameters using the fact that the reconstructed $P(k)$ does not depend on how many polarization data we incorporate in our inversion procedure if and only if the correct values of the cosmological parameters are used. The advantage of this approach is that we need no assumption regarding the functional form of $P(k)$. In this paper, we estimate typical errors in the determination of the cosmological parameters when our method is applied to the PLANCK observation. We investigate constraints on $h$, $\Omega_b$, $\Omega_m$, and $\Omega_\Lambda$ through Monte Carlo simulations.Comment: 18 pages, 15 figures, version to be published in Prog. Theor. Phy