Molecular characteristic of phosphoric acid treated soils

The expansive nature of soils containing high amounts of clay minerals can be altered through chemical stabilization, resulting in a material suitable for construction purposes. The primary objective of this investigation was to study the changes induced in the molecular structure of phosphoric acid stabilized bentonite and lateritic soil using Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR) spectroscopy. Based on the obtained data, it was found that a surface alteration mechanism was the main reason responsible for the improvement of treated soils. Furthermore, the results indicated that the Al present in the octahedral layer of clay minerals were more amenable to chemical attacks and also partly responsible for the formation of new products

Regular Solution Theory Model Used To Predict Supercritical CO2 Extraction Of p-chlorophenol Contaminate From Water Stream.

The objective of this paper is the assessments of the feasibility of the extraction process utilizing a near critical carbon dioxide solvent with p-chlorophenol contaminate solute, which would be speeded up if it were possible to predict mutual solubility data

Temperature effects on the strengh properties of microbially stabilized residual soil

Microbially Induced Calcite Precipitation (MICP) is a rather new technology that has shown greater potential in geotechnical engineering applications. The technique utilizes the concept of microbial involvements in carbonate precipitation within the soil matrix that lead to the improvement in strength and stiffness of the soil. This paper evaluated the effects of temperature variations on the performance of microbial calcite precipitations in residual soil. The soil specimens were cured under different temperature conditions; that are atmospheric temperature, 40, 45 and 50° C. Shear strength, pH and amount of calcite precipitated were determined for each curing condition. A bacterial concentration of 1×105 cfu/ml and 0.5 M concentration of the cementation reagents were used for the study. The results indicated a general increase in strength with increase in curing temperature; which is an indication of temperature influence in bacterial activity. The results so far obtained also revealed that the higher the amount of calcite precipitated the more the strength improvement up to 48 hours treatment duration; after which increase in calcite content does not results in the increase in strength

Discovery of a Non-Thermal Galactic Center Filament (G358.85+0.47) Parallel to the Galactic Plane

We report the discovery of a new non-thermal filament, G358.85+0.47, the ``Pelican'', located ~225 pc in projection from SgrA, and oriented parallel to the Galactic plane. VLA continuum observations at 20 cm reveal that this 7' (17.5 pc) structure bends at its northern extension and is comprised of parallel strands, most apparent at its ends. Observations at 6 and 3.6 cm reveal that the Pelican is a synchrotron-emitting source and is strongly linearly polarized over much of its extent. The spectral index of the filament changes from alpha(20/6)=-0.8 to alpha(6/3.6)=-1.5. The rotation measures exhibit a smooth gradient, with values ranging from -1000 rad/m2 to +500 rad/m2. The intrinsic magnetic field is well-aligned along the length of the filament. Based on these properties, we classify the Pelican as one of the non-thermal filaments unique to the Galactic center. Since these filaments (most of which are oriented perpendicular to the Galactic plane) are believed to trace the overall magnetic field in the inner Galaxy, the Pelican is the first detection of a component of this field parallel to the plane. The Pelican may thus mark a transition region of the magnetic field orientation in the inner kiloparsec of the Galaxy.Comment: 6 pages, 4 figures, to appear in ApJ Letters; Figs. 2 & 3 are color .ps files and best viewed in colo

Synthesized and extending the Bidentate Schiff base complexes using multilayer feedforward neural network

Complexes of Pd(II) and Ni(II) have been synthesized with general composition ML2X2 (M =Pd(II), Ni(II); L = benzylsalicylideneimine and X = OCH3, F). All synthesized compoundshave been characterized using elemental analysis, magnetic susceptibility measurements,infrared and NMR spectral studies that led to the conclusion that the ligands act as bidentatemanner to form square planar geometry for all complexes. As an extending work, the modeldevelopment of these complexes using multilayer feedforward neural network wereperformed. NiL1d, PdL1d, NiL1c and PdL1c were fed to the training network as inputs andbacteria as output. Levenberg Marquardt training algorithm was used during the networktraining with 10 nodes in hidden layer. The results of testing network showed that theregression, R is 1, indicating that the developed model is good. This is supported by the small mean square error (MSE) is 1.948x10-28 at epochs 5. The finding in this study is significant, thus contributed to the design of antibacterial agent especially to the bidentate Schiff base complexes.Keywords: Schiff base, palladium(II), nickel(II), antibacterial, regression, neural network

Optimal rice/colocasia cropping systems in the Ashanti, Eastern and Central regions within the semi-deciduous forest zone of Ghana.

This study is a follow-up survey to investigate the economic viability of the Rice/Colocasia cropping systems introduced by the Root and Tuber Improvement Project (RTIP)/Ministry of Food and Agriculture in the year 2000. It explores the possibility of improving the net earnings of farm families through appropriate farm plans. A Linear Programming model was developed to optimize net income from the Rice and Colocasia enterprises subject to land and labour constraints. The model selected the inter-cropping system as the optimal enterprise in relation to the resources available and allocated 1.2 ha for this cropping system out of the 3 ha available to the typical farm household. The maximum net income obtained from the inter-cropping system for the model farm was ¢4,454,726 ($543.26). There was a binding labour constraint for the first weeding of the farming activities with a shadow price of ¢14.65. Due to labour bottlenecks in certain times of the year, farmers paid unrealistic labour wages of up to ¢8,000 which resulted in low labour productivity in the study area. About 56% of the farmers were females with the younger generation forming the majority (58.9%). Journal of Science and Technology (Ghana) Vol. 27 (2) 2007: pp. 51-6

Phase Equilibrium Data Study With Carbon Dioxide Solvent For 80.52:19.48 Of Ethanoloctane Mixture At Elevated Pressure.

Solubility data of a mixture containing 80.52 % ethanol and 19.48 % octane was measured in carbon dioxide solvent using a high-pressure type phase equilibrium apparatus at pressures up to 100 bar and at temperature of 75 °C. The experimental results showed that considerable separation was not achieved in this ethanol and octane ratio using carbon dioxide

A Low Frequency Survey of the Galactic Plane Near l=11 degrees: Discovery of Three New Supernova Remnants

We have imaged a 1 deg^2 field centered on the known Galactic supernova remnant (SNR) G11.2-0.3 at 74, 330, and 1465 MHz with the Very Large Array radio telescope (VLA) and 235 MHz with the Giant Metrewave Radio Telescope (GMRT). The 235, 330, and 1465 MHz data have a resolution of 25 arcsec, while the 74 MHz data have a resolution of 100 arcsec. The addition of this low frequency data has allowed us to confirm the previously reported low frequency turnover in the radio continuum spectra of the two known SNRs in the field: G11.2-0.3 and G11.4-0.1 with unprecedented precision. Such low frequency turnovers are believed to arise from free-free absorption in ionized thermal gas along the lines of site to the SNRs. Our data suggest that the 74 MHz optical depths of the absorbing gas is 0.56 and 1.1 for G11.2-0.3 and G11.4-0.1, respectively. In addition to adding much needed low frequency integrated flux measurements for two known SNRs, we have also detected three new SNRs: G11.15-0.71, G11.03-0.05, and G11.18+0.11. These new SNRs have integrated spectral indices between -0.44 and -0.80. Because of confusion with thermal sources, the high resolution (compared to previous Galactic radio frequency surveys) and surface brightness sensitivity of our observations have been essential to the identification of these new SNRs. With this study we have more than doubled the number of SNRs within just a 1 deg^2 field of view in the inner Galactic plane. This result suggests that future low frequency observations of the Galactic plane of similar quality may go a long way toward alleviating the long recognized incompleteness of Galactic SNR catalogs.Comment: 31 pages, 9 figures. Figure 7 is in color. Accepted to A

Antibiotic resistance profile of staphylococci from clinical sources recovered from infants

Infants, children and the aged are among the groups most vulnerable to microbial infections more so when these microbial agents become resistant to antimicrobials. The antibiotic resistant profile of Staphylococcus aureus and selected coagulase negative staphylococci were determined by standard methods. Of the 178 staphylococcal isolates evaluated, 122 were S. aureus and the rest coagulase negative staphylococci. 68% of S. aureus isolates were resistant to amoxicillin, 69.8% to cloxacillin, 51% to augmentin and 71% to tetracycline. However, only 2.6% of the 116 S aureus isolates tested were resistant to gentamycin making the drug a reliable therapeutic agent in the event of failure of other antimicrobials in treating staphylococcal infections at least in this community. Resistance to the penicillin drugs was mediated by the elaboration of &#946-lactamase by both pathogenic and non-pathogenic staphylococci. The study shows a high rate of cloxacillin resistance and possibly the existence of methicillin resistance among these strains. 80% of the S aureus strains were multi-resistant with 25% of these resistant to three different antibiotics, 21% to 4 and 6.8% to 6 different drugs. Only 1.2% of these S aureus strains were resistant to 7 different antimicrobials underscoring the need to reduce the high incidence of multi-resistance in this community in the event of an epidemic caused by these strains. The study reveals prevalence of multi-resistance among both pathogenic and non-pathogenic staphylococci in the community.Key words: Staphylococci, Staphylococcus aureus, antibiotics, multi-resistance.African Journal of Biotechnology Vol. 4 (8), pp. 810-82