Miracle-dz/UniFAR-FTUs huggingface dataset:
Evaluation of the bacteriological and physicochemical quality of water supplies in Nsukka, Southeast, Nigeria

The bacteriological and physicochemical quality of various water samples from bore hole, dug well and spring, collected from ten different locations within Nsukka were determined. Total viable and coliform counts were evaluated using the standard plate count method and the most probable number (MPN) technique, respectively. The physicochemical parameters were analyzed using standard methods. The mean total bacteria count of the water samples ranged as follows: bore hole (0.92 × 10 4 to 1.41 × 10 4 ) cfu/ml, well water (1.80 × 10 4 to 2.40 × 10 4 ) cfu/ml and spring water (0.78 × 10, 4 to 1.06 × 10 4 ) cfu/ml. The mean total coliform count of the samples in (MPN/100 ml) ranged as follows: bore hole (10 to 15), well water (14 to 18) and spring water (8 to 10). The isolated and identified bacteria were Enterobacter spp. , Alcaligenes spp. , Escherichia coli , Proteus spp. , Klebsiella spp. , Pseudomonas aeruginosa , Acinetobacter spp. , Staphylococcus aureus and Bacillus sp. The physicochemical values of the water samples ranged as follows: pH (5.6 to 6.4), dissolved oxygen (DO) (5.4 to 6.4), biochemical oxygen demand (BOD) (10.0 to 20.4), chloride (1.6 to 2.3) mg L -1 , total hardness (48.6 to 68.0) mg L -1 , total dissolved solids (6.3 to 9.7) mg L -1 , sulphate (2.0 to 3.4) mg L -1 and nitrate (1.2 to 4.1) mg L -1 . The water supply sources in the present study have good physicochemical attributes for human consumption but the presence of E. coli and other potential enteric pathogens indicated faecal matter contamination of the water implying that they are not suitable for human consumption. Keywords: Drinking water, bacteriological and physicochemical quality, coliforms
Changes in polybrominated diphenyl ether (PBDE) levels in cooked food

Food surveys for levels of toxic chemicals frequently report the levels on an uncooked basis. It is known that cooking may in some conditions decrease the amount of dioxins and related chemicals in food. Surveys of polybrominated diphenyl ether (PBDE) levels in food to date show data from uncooked food only. In this article, it was shown that broiling, with fat dripped from the foods reported here, ground beef, ground lamb, catfish, trout, and salmon, reduces the amount of PBDEs in these foods. This suggests that calculations of food intake need to take into consideration levels in the cooked food rather than in the uncooked food.
Miscibility of polymethylmethacrylate and polyethyleneglycol blends in tetrahydrofuran

The miscibility of polymethylmethacrylate (PMMA) and polyethyleneglycol (PEG) blends in tetrahydrofuran (THF) has been investigated by viscosity, density, refractive index, and ultrasonic velocity studies. Various interaction parameters such as polymer–solvent and blend–solvent interaction parameters and heat of mixing have been calculated using the viscosity, density, and ultrasonic velocity data. The results indicated the existence of positive interactions in the blend polymer solutions and that they are miscible in THF in the entire composition range. The study also revealed that variation in the temperature does not affect the miscibility of PMMA and PEG blends in THF significantly. The presence of hydrogen bonding in the blends in the solid state has also been indicated by FTIR studies. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Powder Characteristics of Pantoprazole Delivery Systems Produced in Different Spray-Dryer Scales

ABSTRACT The purpose of this study is to investigate the physical characteristics of pantoprazole-loaded enteric microparticles produced in different spray dryers and operational conditions. In all conditions tested it was possible to obtain powders that presented spherical shape microparticles, with mean sizes from 6.7 to 24.5 µm. The size was affected mainly by initial feed concentration (2.2 or 6.6% w/w). The integrity of microparticles affected surface area (24 to 113 m2/g)and drug release (71 to 98%). All powders presented very poor flow. The powder that presented higher release was produced with 6.6% solution and a rotating disc atomizer.
Deuterium Effect on Thermal Decomposition of Deuterated Gap: 1. Slow Thermal Analysis with a TGA-DTA-FTIR-MS

The knowledge of the degradation mechanisms of propellants is a key factor in understanding some performance issues of chemical propulsion systems. The thermal decomposition of GAP and a deuterated analog was studied. Thermogravimetric analyses coupled to differential thermal analysis, Fourier transform infrared spectrometry, and mass spectrometry were employed to evaluate the complete decomposition profile of GAPs. Evidence of labeled gaseous compounds were found both in mass spectra and in the FTIR spectra, where new frequencies associated with isotopic labeled gaseous products were detected. An imine-bearing species was detected among the decomposition products, apparently originating from the breakdown of the azide group.
Sources and composition of submicron organic mass in marine aerosol particles

The sources and composition of atmospheric marine aerosol particles (aMA) have been investigated with a range of physical and chemical measurements from open‐ocean research cruises. This study uses the characteristic functional group composition (from Fourier transform infrared spectroscopy) of aMA from five ocean regions to show the following: (i) The organic functional group composition of aMA that can be identified as mainly atmospheric primary marine (ocean derived) aerosol particles (aPMA) is 65 ± 12% hydroxyl, 21 ± 9% alkane, 6 ± 6% amine, and 7 ± 8% carboxylic acid functional groups. Contributions from photochemical reactions add carboxylic acid groups (15%–25%), shipping effluent in seawater and ship emissions add additional alkane groups (up to 70%), and coastal or continental emissions mix in alkane and carboxylic acid groups. (ii) The organic composition of aPMA is nearly identical to model‐generated primary marine aerosol particles from bubbled seawater (gPMA, which has 55 ± 14% hydroxyl, 32 ± 14% alkane, and 13 ± 3% amine functional groups), indicating that its overall functional group composition is the direct consequence of the organic constituents of the seawater source. (iii) While the seawater organic functional group composition was nearly invariant across all three ocean regions studied and the ratio of organic carbon to sodium (OC/Na+) in the gPMA remained nearly constant over a broad range of chlorophyll a concentrations, the gPMA alkane group fraction appeared to increase with chlorophyll a concentrations (r = 0.66). gPMA from productive seawater had a larger fraction of alkane functional groups (42 ± 9%) compared to gPMA from nonproductive seawater (22 ± 10%), perhaps due to the presence of surfactants in productive seawater that stabilize the bubble film and lead to preferential drainage of the more soluble (lower alkane group fraction) organic components. gPMA has a hydroxyl group absorption peak location characteristic of monosaccharides and disaccharides, where the seawater organic mass hydroxyl group peak location is closer to that of polysaccharides. This may result from the larger saccharides preferentially remaining in the seawater during gPMA and aPMA production.
Synthesis of Particular Symmetrical Mesoporous Silicon Dioxide Sphere

In this study, two particle sizes of mesoporous silicon dioxide spheres (sample A and B) were synthesized with didecytrimethylammonium bromide as template, and tetraethyl orthosilicate (TEOS) as the silica source. The particles of the samples were extraordinarily uniform and regular. The diameters of the spheres were 439 ± 5 and 485 ± 5 nm. The samples were stable up to 1000°C. The samples revealed only one stage of the weight loss, and the slightly endothermic weight loss was 7.3% for sample A and 9.1% for sample B. It showed that the prepared samples had the higher thermal stability.
Relations entre stabilité de l'agrégation et matière organique totale et soluble à l'eau chaude dans des sols ferrallitiques argileux (Congo, Brésil)

Organic matter (OM) generally plays an important role in soil aggregate stability. The objective of this work was to characterize the hot water-extractable OM and its role in the aggregate stability of clayey ferrallitic soils under different land use management. The macroaggregate (>200 µm) stability of these soils was determined before (AS) and after hot-water extraction (ASe). The contents in total organic carbon and in carbon present as carbohydrates, as well as the sugar composition, were determined on the bulk soils and their hot-water extracts.The carbon and macroaggregate contents decreased upon land-clearing and cultivation, but to a lesser extent when some cultural practices were used. Whatever the situation considered, the hot-water extract always presented a higher carbohydrate content than the bulk soil. The high values of ratios r = (galactose + mannose)/(arabinose + xylose) suggested that a large proportion of carbohydrates was of microbial origin. There were significant correlations betwee.
Low temperature synthesis of magnesium oxide and spinel powders by a sol-gel process

Magnesium oxide and magnesium aluminate (MgAl2O4) spinel (MAS) powders have been synthesized by a simple aqueous sol-gel process using citrate polymeric precursors derived from magnesium chloride, aluminium nitrate and citrate. The thermal decomposition of the precursors and subsequent formation of cubic MgO and MAS were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry-differential scanning calorimetry (TG-DSC) and Fourier transform infrared spectra (FTIR). The single phase cubic MgO powder and MAS powder form after heat treatment at 800 and 1200 °C, respectively. The particle size of the MgO and MAS powders is about 100 nm and several micrometers, respectively. Ball milling eliminates the size of MgO and MgAl2O4 spinel powders by decreasing the conglomeration of the powders.
27Al and 29Si MAS NMR Study of Kaolinite Thermal Decomposition by Controlled Rate Thermal Analysis

The processing of kaolinite under controlled rate thermal analysis conditions (CRTA) provides homogeneously transformed samples at defined dehydroxylation rates. The kaolinite-to-metakaolinite transformation has been monitored by solid-state NMR and X-ray diffraction. The metakaolinite product is an amorphous material with no resolved XRD pattern and is based on a disordered polymerized silicon/aluminum network in which aluminum preferably occupies four- and five-fold structural positions in the ratio 60% AlVI, 30% AlV, and 10% AlVI. This complex dehydroxylation process has been viewed at different scales, with the aluminum NMR tracing a site-by-site destructon of the octahedral sheet and the silicon NMR and XRD following a more rapid destruction of the longrange order.
Saturated Pressure Measurements of Dimethyl Ether at Temperatures from (219 to 361) K

The vapor pressure data of dimethyl ether (RE170), an ozone-friendly refrigerant, was measured using a constant-volume apparatus. Measurements were carried out at temperatures from (219 to 361) K and at pressures from (22 to 2622) kPa. A total of 71 experimental points were obtained. The measurements were fitted to a Wagner-type equation and an absolute deviation of 0.26 %. After a literature survey of the saturated pressure experimental findings, our experimental results were compared with the REFPROP 7.0 prediction together with the published data.
On The Fluid Dynamics of Virtual Impaction and The Design of a Slit Aerosol Sampler

Title of dissertation: ON THE FLUID DYNAMICS OF VIRTUAL IMPACTION AND THE DESIGN OF A SLIT AEROSOL SAMPLER Marwan L. Charrouf, Doctor of Philosophy, 2006 Dissertation directed by: Professor Richard V. Calabrese Department of Chemical & Biomolecular Engineering It has been long established that Reynolds number effects can lead to flow instabilities and/or transition from laminar to turbulent flow regimes. The nature of free shear jets is well understood and heavily covered in the fluid mechanics literature. On the other hand, the study of confined nozzles presents some challenges and is still a developing area of research. In this work, we focus on quasi-impinging jets, such as the ones feeding into a virtual impactor. Virtual impactors are popular, inexpensive aerosol collection devices capable of separating airborne solid particles. Recently they found increased application in areas that require concentration of dilute aerosols, such as biological-laden flows. In essence, this research is motivated by the need to fundamentally understand the fluid-particle interaction mechanisms entailed during virtual impaction. To this end, we rely on theoretical insight gained by numerical analysis of the classical equations within a one-way coupled Lagrangian framework. In the first part of this investigation we perform a direct transient simulation of the two-dimensional incompressible Navier-Stokes equations for air as the carrier phase. The momentum and continuity equations are solved by FLUENT. The solutions of three separate computations with jet Reynolds numbers equal to 350, 2100, and 3500 are analyzed. The 2-D time-mean results established the nature of the jet potential core and clarifications about the role of the Reynolds number were proposed. Transient analysis deciphered the characteristics of the mirrored Kelvin-Helmholtz instability, along with particle-eddy interaction mechanisms. In the second part we perform a large eddy simulation (LES) on a domain of a real-life sampler. The Lagrangian dynamic residual stress model is implemented and validated for two canonical turbulent flows. The newly contrived code is then applied to the study of a prototype device. A three-dimensional growth mechanism is proposed for the jet mixing layers. The Lagrangian dynamic model LES exhibited significant regions of high subgrid turbulent viscosity, compared to the dynamic Lillymodel simulation, and we were able to identify the origin, and learn the dynamics of five key coherent structures dominant during transition. Comparison with preliminary experimental data for the aerosol separation efficiency showed fairly good agreement. ON THE FLUID DYNAMICS OF VIRTUAL IMPACTION AND THE DESIGN OF A SLIT AEROSOL SAMPLER
Milk Fat Production Trend and Effect of Season on it at Sree-Nagor Milk Shed Area under Milk Vita Throughout the Year

1 Abstract: This study was undertaken to find out the milk fat production trend both in qualitative and quantitative aspect and seasonal effect on it at Sree-Nagor Milk Shed Area (MSA) under Milk Vita in Munshigonj, Bangladesh. The experiment was conducted during the period of 1995 to 1999. Season had the tremendous effect on milk yield (l/d). The milk production showed highest in the month of June, lowest in January, August, September and December; but in other months of the year it seemed almost similar. However, the average fat value of milk at Sree-Nagor MSA followed almost a specific trend throughout the year. Furthermore, the average fat value of Sree-nagor MSA was in-significant (P>0.05) between different months of the experimental period, but that of each year (1995-1999) between different months were highly significant (P<0.01), which means that season has large effect on fat value.
New developments in green LEDs

Green InGaN LEDs showed great improvements over the last decade, but still perform not as good as blue InGaN LEDs. Brightness, Efficiency and sub‐linearity of brightness versus driving current (“droop”) are significantly lower for a 530 nm green LED than for a 440 nm blue LED. Assuming an indirect Auger effect as one of the major loss mechanisms in InGaN LEDs, a reduction of the carrier density per emitting well is the key for efficiency improvement for green LEDs. An optimized multiple quantum well (MQW) structure with multiple emitting wells at 525 nm is compared to a single quantum well LED structure. A color‐coding scheme was used to investigate MQW operation: up to four MQWs contribute to the green emission at 525 nm. Packaged 1 × 1 mm2 ThinGaN® chips emit up to 109 lm (209 mW) at 350 mA and 170 lm (339 mW) at 700 mA, the efficacy was 90 lm/W and 66 lm/W, respectively. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Frictional characteristics of single and polycrystalline muscovite and influence of fluid chemistry

Frictional experiments were carried out on powder and single crystal specimens of muscovite. Friction coefficients for powder samples were found to be about twice as large as those for single crystals. We found that whereas in single crystal samples sliding occurs along the (001) plane, the situation is more complicated in powder samples. Experiments under wet conditions showed an ~30% reduction in friction coefficient for both powder and single crystal samples compared with dry conditions. The degree of the reduction depended on the fluid chemistry of NaCl or CsCl solutions, indicating that the presence of adsorbed water reduced the friction coefficients. Surface flatness of gauge particles and high affinity of the surface to water were crucial for realizing the effective lubrication due to adsorbed water.
EPR of gamma irradiated single crystals of cholesteryl benzoate

The cholesteryl benzoate compound has been irradiated with 60Co-γ rays at room temperature. The irradiated samples have been examined for paramagnetic resonance, and in several cases the observed spectra could be identified with specific radicals. In each case the results have been considered in relation to the present knowledge of the radiation chemistry of the compound. The single crystals have been investigated between 123 and 300 K. The spectrum parameters are found to be temperature independent. Radiation damage centers are attributed to ĊHCH2 and ĊHCH2CH2 radicals. The g values and the hyperfine coupling constants of the unpaired electron with the protons were determined.
Simulation of a three-step one-column pressure swing adsorption process

Separation of a binary mixture by a three-step one-column pressure swing adsorption process in isothermal and adiabatic cases has been studied. The separation performance of the process is characterized by three parameters: enrichment, recovery and productivity. It has been compared at various operating conditions. The evolution of the bed performance from cycle to cycle and the bed dynamics at cyclic steady state have also been addressed.
Direct Dynamics Study on the Hydrogen Abstraction Reaction PH 3 + H → PH 2 + H 2

The hydrogen abstraction reaction PH3 + H → PH2 + H2 has been studied using an ab initio direct dynamic method. The optimized geometries and frequencies were calculated at the UQCISD/6-311+G** level for the reactant, products, and transition state, as well as 12 points along the minimum energy path. In order to obtain more reliable energies, the single-point calculations were carried out at the G2//QCISD level. The potential barriers obtained for the forward and reverse reactions are 3.24 and 25.99 kcal/mol, respectively. Reaction rate constants and activation energies were calculated for the temperature range 200−1600 K by the canonical variational transition state theory incorporating a small-curvature tunneling correction, and they are in satisfactory agreement with the available experimental values over the measured temperature ranges.
Some Physiological Responses of Black-Eyed Pea to Iron and Magnesium Nanofertilizers

Key players in photosynthesis, iron (Fe) and magnesium (Mg), in nano and common forms were considered for foliar application of black-eyed pea. Factorial experiments in three replicates were designed based on completely randomized blocks containing Fe (0, 0.25, and 0.5 g L−1; in two forms: nano and common) and Mg (0, 0.5 g L−1 nano, and 0.5 g L−1 common). The elements were applied 56 and 72 days after sowing over the leaves, and data were collected after day 85. Iron had significant effect on yield, leaf Fe content, stem Mg content, plasma membrane stability, and chlorophyll content. The greatest effect was obtained by two treatment combinations of 0.5 g L−1 common Fe + 0.5% nano-Mg and 0.5 g L−1 common Fe + 0.5 g L−1 common Mg. In general, almost all analyzed traits were improved by foliar application of these two elements, probably as a result of more efficient photosynthesis.
Atrazine Degradation in Subsurface Soil by Indigenous and Introduced Microorganisms

Significant atrazine degradation (50%) but only 1% mineralization was detected in samples taken from the upper soil layer (0−25 cm), but not in samples taken from deeper horizons. Thin layer chromatography analysis of noninoculated soil indicated dealkylation to be a major degradation pathway with deethylatrazine favoring deisopropylatrazine. Inoculation with Pseudomonas sp. strain ADP (P.ADP) resulted in 90−100% mineralization of [14C]atrazine in all samples after 15 days. Atrazine was degraded in the soil via dechlorination as the first mineralization step. C-source competition was not responsible for differences in initial mineralization rates. Higher organic matter content in the upper soil level did not result in a sorption-related decrease in degradation rates. It is concluded that the limiting factor for atrazine mineralization in the tested soil profiles was the absence of atrazine-mineralizing microorganisms. Therefore, bioaugmentation may be preferable to enhancement of intrinsic atrazine-degrad.
Spectroscopy of Molecular Junction Networks Obtained by Place Exchange in 2D Nanoparticle Arrays

Well ordered nanoparticle arrays were prepared on Si/SiO2 surfaces from alkanethiol-coated Au nanoparticles via self-assembly and micro-contact printing. We study the insertion of conjugated molecular species within the nanoparticle arrays via spectroscopic and electrical transport measurements. Upon exchange of the alkanethiol chains with the conjugated oligomers, the conductance of the network increases by one to 3 orders of magnitude. In addition, the absorption spectra in the visible light range show a red-shift of the surface plasmon resonance (SPR). The latter shift, which is due to the difference in permittivity between alkanes and conjugated oligomers, can be understood within Mie and Maxwell−Garnett theory. Finally, infrared absorption spectra provide direct spectroscopic evidence that the conjugated oligomers can be not only inserted but also, subsequently, fully removed from the nanoparticle arrays via place-exchange. The reversibility of the exchange process demonstrates the potential of these.
Solid-liquid extraction of oils of African elemi's (Canarium schweinfurthii's) fruit

African elemi (Canarium schweinfurthii) contains oil in its fruit's pulp and kernel. Solvent extraction of these oils using n-hexane was investigated in this work to obtain some process parameters. This was done at different temperatures (30℃ - 55℃) over a period of time (30 - 240 min) with varying solvent to feed (solid) mass ratios. Oil yield and extraction efficiency were observed to increase with time, temperature and materials ratio but in different fashions. The kinetics of the oils' extraction was found to be adequately described by Peleg equation and a variant of it. At 30℃, kernel oil recorded the highest saturated extraction yield (Cs) with 7.5 g solvent/g solid while no peak was observed for pulp oil extraction using 1 to 10 g solvent/g solid. Kernel oil gave the highest saturated (maximum) yield (45.93 g/100 g solid) but pulp oil gave the highest initial extraction rate (Bo=3.5868 g/L.min) and fastest time constant (τo=9.84 min). Free fatty acid content of the extracted oils was observed to increase with leaching temperature while the iodine value reduced with it. This phenomenon was more pronounced with kernel oil.