Miracle-dz/UniFAR-FTUs huggingface dataset:
Oil Pollutiona and Its Impact on Water Quality in Ibeno Community

A comparative study on the impact of oil pollution on water quality in both the oil and non - oil bearing communities of Ibeno and Mbo respectively was conducted. The mean concentration of Pb, (0.20 mg/l) Cd (0.1 mg/l), Cr (0.10 mg/l) and Ni (<0.10 mg/l) were above the WHO recommended limits of 0.05 mg/l, (Pb) 0.005 mg/l (Cd), 0.05 mg/l (Cr) and 0.02 mg/l (Ni) for drinking and domestic water quality. The physicochemical properties in both oil (incident zone and non-oil (control zone) trialed below standards. The mean Ph (5.41) for incident zone and Ph (4.73) for control zone were below the recommended range of 6.5-8.5. BOD varied between 0.5 to 20 mg/l in the incident zone and 0.50 mg/l in the control zone. The Do ranged from 2.7 mg/l to 11.6 mg/l in the incident zone and a mean concentration of 6.4mg/l in the control zone whereas WHO (1993) recommended level is 5 mg/l. Turbidity was higher in all samples above WHO recommended level of 5NTU. The mean values for hydrocarbons (range between <0.003-0.004 mg/l for BTEX were generally below some local and international standards (0.01 mg/l for benzene, 0.7 mg/l for toluene). The regulatory limits (0.0002 mg/l) are stipulated by Department of Petroleum Resources DPR.
Low temperature direct bonding of silicon and silicon dioxide by the surface activation method

Low temperature bonding of Si and SiO/sub 2/ by the surface modification in a vacuum was examined. For the bonding of Si wafers, surface cleaning by Ar beam etching was effective to improve the bonding prepared in the vacuum at room temperature. The strength was equivalent to that of conventional wafer bonding with high temperature annealing. For the bonding of SiO/sub 2/ both Ar beam and H/sub 2/O beam treatment were applied. SiO/sub 2/ bonding strength was about a half of Si bonding. The influence of surface oxidation was also examined by exposing etched Si surface to residual gas in a vacuum chamber. Long time exposure before bonding caused the reduction of bonding strength. These results mean that oxidized surface has less bonding ability than clean surface etched by Ar beam at the room temperature.
Chlorinated polyethylene (CPE)/ethylene methacrylate copolymer (EMA)/sepiolite nanocomposite via a facile one-step covalent modification technique

The work reports a facile one step covalent modification technique of sepiolite needles by in situ polymerization of e-caprolactone. The effective modification of sepiolite was confirmed by Fourier transform infrared (FTIR), X-ray diffraction (XRD), High Resolution-Transmission Electron Microscopy (HR-TEM) and water contact angle measurements. Nanocomposites of chlorinated polyethylene (CPE)/ethylene methacrylate copolymer (EMA) blend (60/40 ratio) were prepared by melt mixing the polymer blend with the pristine and poly(e-caprolactone) modified sepiolite (PCL-g-SP). For the ease of comparison, equal filler content in both the nanocomposites was maintained (5 wt%). The effect of modified sepiolite on the mechanical and thermal properties of CPE/EMA blend of 60/40 ratio was precisely studied by ultimate tensile testing, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). The modified sepiolite based nanocomposite showed a considerable improvement of 47.77% in ultimate tensile strength over the neat blend. Besides, a high char yield content of both the nanocomposites, increments of 38.4% and 39.6% in the initial degradation temperature (Ti) values of pristine and modified sepiolite based nanocomposites respectively were observed compared to the neat blend system.
Ultraviolet/visible/near-infrared spectral analysis and chemometric tools for the discrimination of wines between subzones inside a controlled designation of origin: a case study of Rías Baixas

Background and Aims Chemometrics combined with ultraviolet (UV), visible (VIS) and near-infrared (NIR) spectral analysis were evaluated to classify wines belonging to the controlled designation of origin (DO) Rias Baixas (Spain). Methods and Results Samples of wines made solely from the Albarino cultivar from subzones Condado, Salnes, Rosal and Ribeira do Ulla were analysed in transmittance mode using UV, VIS and NIR ranges alone or in combination. Principal component analysis was used to explore and determine data patterns. Soft independent modelling of class analogy (SIMCA), linear discriminant analysis and support vector machine classification were used to classify the samples. Condado wines were completely classified by applying SIMCA to the UV/VIS/NIR, NIR or VIS/NIR spectral ranges. Salnes and Ribeira do Ulla wines were completely classified by applying SIMCA to the UV/VIS spectral range. Finally, Rosal wines were completely classified by applying linear discriminant analysis to the VIS/NIR spectral range. Conclusions These results show that combinations of UV/VIS/NIR spectra and chemometric methods can be used as a rapid technique to classify subzones into a DO such as Rias Baixas. This technique may also assist authentication because the models also discriminated wines from outside Rias Baixas. Significance of the Study The importance of spectral range selection and chemometric tools for the classification of wines inside a DO was demonstrated.
The Influence of Glimepiride on the Biochemical and Histomorphological Features of Streptozotocin - Induced Diabetic Rabbits

An experiment was conducted to study the efficacy of glimepiride (a new sulphonylurea) on the biochemical values and histomorphological features of streptozotocin-induced diabetic rabbits. Eighteen New Zealand white male rabbits were selected for the study. The rabbits were randomly divided into three Groups of six each. Group I was kept as normal healthy control (NC), Group II and Group III were made diabetic by single intravenous administration of streptozotocin (@ 65 mg/kg. b.w.). Glimepiride was given to Group III rabbits by gavage @ 2mg/kg. b.w. daily for twenty-one days whereas Group I and Group II rabbits received normal saline in the similar manner. The results indicated a significant decrease in the blood sugar (P<0.01), blood urea (P<0.001) and serum creatinine (P<0.001) in Group III rabbits. Further, the histomorphological study showed an increase in the percentage of beta cells in pancreatic islets and recovery of renal tubules in Group III rabbits. The findings indicate that glimepiride improves the biochemical values and ameliorates the histopathology of diabetic rabbits particularly restoring the morphology of beta cells of islets of Langerhan’s and thus, seems to be encouraging.
Urea Phosphoric Acid as a Quality-Control Reagent for the Poly-Set Process

Native cotton was modified with methylated methylolmelamine in combination with dimethyloldihydroxyethyleneurea by a two-step treatment similar to that of the Poly-Set process. Physical properties were determined before and after urea phosphoric acid (UPac) hydrolysis to determine if the stripping action of UPac could be used in quality control in the Poly-Set process. UPac does provide a means of correcting treatment errors occurring at any stage of the Poly-Set treatment.
Molecular Assembly with Axial Cyanato Ligands and Paddlewheel Tetracarboxylatodiruthenium(II,III) Fragments

Homo and heteropolymetallic chains constructed with [Ru2(μ-O2CR)4]+ building blocks and OCN– and [Ag(OCN)2]– connectors are described. In the complexes [Ru2{μ-O2CC(Me)=CHEt}4(OCN)]n (1) and {[Ru2(μ-O2CMe)4][Ag(OCN)2]}n (2) an infrequent μ1,1-O coordination mode of the OCN– ligand is observed. In addition, the formation of a Ag–OCN bond instead of the Ag–NCO coordination mode, which is more usual, is noteworthy in complex 2. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Defects and impurities in thermal oxides on silicon

Oxides grown at 1100 °C in dry oxygen for 60 min to a thickness of 1350 A on silicon with and without subsequent forming gas anneals were 60Co γ irradiated at 4 K with doses up to 106 rad (Si). In situ electron paramagnetic resonance measurements at 10 K revealed ≊3×1017 atomic hydrogen/cm3 and ∼1017 oxygen‐hole centers/cm3 in the oxide. The paramagnetic dangling bond on the silicon side of the Si/SiO2 interface (Pb center) was also observed. The (relative) concentration of these centers was measured as a function of isochronal annealing between 10 and 300 K.
Dipolar cooperative motion in amorphous azo copolymers: a molecular addressing possibility

Copolymers containing rigid azobenzene and ester side groups linked by relatively short spacers to the main chain form amorphous films. Such films can be addressed with polarized laser light to produce oriented domains. Birefringence measurements and time dependent infrared spectroscopy are used to analyze the orientation. Two series of copolymers are analyzed in comparison. The first consists of copolymers of 4'-{[2-(methacryloyloxy)ethyl] ethylamino}4-nitroazobenzene (DR1M) and 4-{[2- ((2-methyl-1-oxo-2-propenyl)oxy)ethyl]oxy}benzoate (BEM), where both the azo and the ester rigid groups have similar dipole moments. The second series consists of copolymers of DR1M with a much less polar 4-phenyl-4- {[2-(2-(2-methyl-1-oxo-2- propenyl)oxy)ethyl]oxy}benzoate (NBEM). Birefringence studies clearly suggest that in poly(DR1M-co- BEM), the BEM groups are being oriented by 'sympathy' with the DR1M groups, while in poly(DR1M-co-NBEM) no such cooperative motion is apparent. Time dependent infrared spectroscopy can analyze separately the motions of each of the rigid groups, and it clearly shows that the BEM groups are being moved by the DR1M groups, while the orientation of the NBEM groups is much lower. Thus one can envisage materials where cooperative motion is present (polar groups), or where only the polar azobenzene groups are 'molecularly addressed' by the laser, with the non-polar rigid groups remaining relatively inert. The consequences to formation of surface gratings on these copolymer films are discussed.
Chemical polymorphism of essential oils of Hyptis suaveolens from El Salvador

Wild growing, ﬂowering Hyptis suaveolens (L.) Poit. (Lamiaceae) from 15 populations from El Salvador was collected and hydrodistilled. The resulting essential oils were analyzed by GC-MS. Principal component analysis of concentration data from 32 compounds showed differences of the chemical composition according to the geographic origin. In the southern area a fenchone–fenchol–chemotype was predominant, whereas in the northern regions the plants mostly accumulated 1,8-cineole. The essential oils of two collection sites from the southeast revealed high yields of α-terpinolene and sabinene. Some populations, however, showed unsteady compositions, indicating that intrapopulational chemical polymorphism occurs in Hyptis suaveolens. Copyright © 2004 John Wiley & Sons, Ltd.
Metal Complexes of Ergothioneine

The interaction between ergothioneine and divalent metal ions has been investigated by means of potentiometric titration, visible and near-infrared spectra. The order of the relative formation constants of erogothioneine-metal complexes was Cu (II)>Hg (II)>Zn (II)>Cd (II)>Co (II)lNi (II). For ergothioneine-cobalt (II) complex, the crystal field parameter (Dq) and Racah interelectron repulsion parameter (B) calculated were 453 and 971 cm-1, respectively. It was indicated that ergothioneine coordinates to cobalt (II) ion through its sulfur atom and forms a distorted tetrahedral complex.
Humectants To Augment Current From Metallized Zinc Cathodic Protection Systems on Concrete

Cathodic protection (CP) systems using thermal-sprayed zinc anodes are employed to mitigate the corrosion process in reinforced concrete structures. However, the performance of the anodes is improved by moisture at the anode-concrete interface. Research was conducted to investigate the effect of hydrophilic chemical additives, humectants, on the electrical performance and service life of zinc anodes. Lithium bromide and lithium nitrate were identified as feasible humectants with lithium bromide performing better under galvanic CP and lithium nitrate performing better under impressed current CP. Both humectants improved the electrical operating characteristics of the anode and increased the service life by up to three years.
DISTRIBUCIÓN DE PLOMO EN SUELOS CONTAMINADOS EN EL ENTORNO DE UNA PLANTA DE RECICLAJE DE BATERÍAS ÁCIDAS

Total Pb, Cd, Cu, Ni and Zn concentrations and the distribution of lead in soils from a farmland near a battery recycling plant in Madrid (Spain) were investigated to establish a possible relationship with a recent episode of horses death that presented lead intoxication symptoms before dying. Total Pb and Cd levels presented a clear decrease with distance to the battery recycling plant, ranging from 5906 to 171 mg Pb/kg soil and 11.0 to 1.58 mg Cd/kg in soils from 40 to 400 m from the plant. A five-step chemical fractionation procedure revealed that lead was mainly in the non residual fractions that accounted for more than 96 % of total lead in the most polluted soils. Acidification caused by acid effluents from the recycling plant drecreased markly the pH of the soils (from aprox. 7.0 to 3.14) and increased the soil Pb extracted in the soluble and exchangeable fraction for more than 37 % of Pb total soil.
Solar spectral influence on the performance of photovoltaic (PV) modules under fine weather and cloudy weather conditions

The performance of photovoltaic modules is influenced by solar spectrum even under the same solar irradiance conditions. Spectral factor (SF) is a useful index indicating the ratio of available solar irradiance between actual solar spectrums and the standard AM1·5‐G spectrum. In this study, the influence of solar spectrum on photovoltaic performance in cloudy weather as well as in fine weather is quantitatively evaluated as the reciprocal of SF (SF−1). In the cases of fine weather, the SF−1 suggests that solar spectrum has little influence (within a few %) on the performance of pc‐Si, a‐Si:H/sc‐Si, and copper indium gallium (di)selenide modules, because of the “offset effect”. The performance of a‐Si:H modules and the top layers of a‐Si:H/µc‐Si:H modules can vary by more than ± 10% under the extreme conditions in Japan. The seasonal and locational variations in the SF−1 of the bottom layers are about ± several %. A negative correlation is shown between the top and bottom layers, indicating that the performance of a‐Si:H/µc‐Si:H modules does not exceed the performance, at which the currents of the top and bottom layers are balanced, by the influence of solar spectrum. In the cases of cloudy weather, the SF−1 of the pc‐Si, a‐Si:H/sc‐Si, and copper indium gallium (di)selenide modules is generally higher, suggesting favorable for performance than that in fine weather. Much higher SF−1 than that in fine weather is shown by the a‐Si:H module and the top layer of the a‐Si:H/µc‐Si:H module. The SF−1 of the bottom layer neither simply depend on season nor on location. Copyright © 2011 John Wiley & Sons, Ltd.
Theoretical estimations of thermodynamic properties of liquid mixtures by Flory's statistical theory

Flory's statistical theory has been employed for the computation of ultrasonic velocity (u), density (ρ), internal pressure (P i), thermal expansion coefficient (α), isothermal compressibility (β T), adiabatic compressibility (β S), heat capacity at constant pressure (C P), heat capacity at constant volume (C V), heat capacities ratio (γ), pseudo-Gruneisen parameter (Γ), excess volume (V E) and excess heat capacity at constant pressure ( ) at varying temperatures for 10 binary and 5 ternary systems. The binary systems under investigation are: acetonitrile + benzene, benzene + DMF, acetonitrile + DMF, cyclohexanol + cyclohexane, piperidine + tetrahydropyran, piperidine + cyclohexane, tetrahydropyran + cyclohexane, benzene + p-xylene, benzene + p-dioxan, acetone + methyliodide, and the ternary systems are: benzene + chloroform + cyclohexane, toluene + chloroform + cyclohexane, chlorobenzene + chloroform + cyclohexane, dioxane + chloroform + cyclohexane and chlorobenzene + cyclohexane + n-heptane. The results of calculations show that for all the systems under consideration, the calculated values of various thermodynamic parameters show the same trend as observed experimentally. Fairly good agreement is found between theoretical and experimental values. The ultrasonic velocity of liquid mixtures is obtained using the most popular Flory theory without the help of any empirical relation.
Solid phases and solution species of different elements in geologic environments

An investigation was conducted to predict from thermodynamic data the nature of the solid phases and solution species in various weathering environments of different elements (Am, Sb, Ce, Cs, Co, Cm, Eu, I, Np, Pu, Pm, Ra, Ru, Sr, Tc, T, U, and Zr) that are present in radioactive wastes, to predict the degree of adsorption of different elements by the solid matrices and to compare these predictions with observed results, and to determine the influence of different factors (such as Ph, Eh, complexing ligands) on total pore-water concentration and the nature of solution species of selected elements. Based on the nature of the predominant solution species, qualitative predictions regarding the adsorption and movement of various elements can be made. Soils and sediments mainly show cation exchange capacities (since these materials carry a large net negative charge) and to a limited extent, anion exchange capacities. Thus, most cations migrate through the soil or rock column at speeds slower than the groundwater. Relative to each other, the trivalent cations generally move the slowest, the divalent cations at intermediate velocities and the monovalent cations most rapidly. Tritium is unique in that it readily substitutes for hydrogen in water and migrates, therefore, atmore » the same velocity as water. The simple anions tend to migrate through soils and rocks with little reaction because usually a pH of less than 4 is required to activate a significant soil anion exchange capacity. The migration and retention of inorganic complex species (mononuclear and polynuclear) would also be dependent upon the charge and size of the species. The behavior of organic complexed species of elements is difficult to predict because of the lack of knowledge regarding the exact nature of the organic ligands, a wide variation in amounts and types of organic ligands, and the size and solubility of these organics. « less
The vertical zonation of adpressed diatoms and other epiphytic algae on Phragmites australis

The seasonal colonization and vertical zonation of adpressed and upright algae on Phragmites stems in Lake Belau, Germany, was investigated from November 1988 to October 1991. During the autumns and winters from 1988 to 1990 the dominant adpressed species included the diatoms Epithemia adnata, E. sorex, E. turgida and Rhopalodia gibba, while during the same seasons in 1990 and 1991, Cocconeis placentula var. euglypta was abundant. The upright diatoms were most abundant on the middle sections of the stems, whereas those epiphytes with most of their cell surfaces directly in contact with the substratum constituted the greatest part of the biomass on the lowest sections of the stems. Epithemia spp. and R. gibba attained their highest abundances near the sediment as well as buried beneath the most dense periphyton aggregations, while there were dense populations of C. placentula var. euglypta on the entire surface of the stems. Cocconeis is able to tolerate higher light intensities, with photosynthetically ac.
Computing PI and Szeged indices of multiple phenylenes and cyclic hexagonal-square chain consisting of mutually isomorphic hexagonal chains

PI and Szeged indices are two of the most important topological indices defined in chemistry. In this study, the PI and Szeged indices of linear (n)-phenyl- enes and a cyclic hexagonal-square chain consisting of n mutually isomorphic hexa- gonal chains were computed. The PI and Szeged indices of a multiple phenylene, which is the 2-dimensional case of a phenylenic nanotube and nanotorus, were determined.
Effect of Hydroacoustic Cavitation Treatment on the Spiral Processing of Bituminous Coal

Testing was conducted to evaluate the effects of hydroacoustic cavitation (HAC) treatment on spiral separation when processing nominal −1500 µm Illinois-basin bituminous coal. Cavitation was produced either by flow through an ultrasonic resonator chamber or enhanced cavitation by initial flow through a cavitation box followed by flow through the ultrasonic chamber. After treatment, the slurry was passed through a hydrocyclone for desliming, and the underflow stream was used as spiral feed. Spiral tests were carried out using a two-stage spiral at three volumetric flow rates for different HAC treatment conditions. HAC treatment reduced the overall size distribution of the spiral feed material. Likewise, desliming of the treated material led to a reduction in the ash values for each size interval. For example, after HAC treatment, the ash value of the deslimed material was reduced to 25% compared to 41% for the untreated deslimed material. Subsequent spiral separation of the treated material produced clean coal with an ash value of 15% at a yield of 79% compared to an ash value of 18% at a yield of 59% for the untreated material. HAC treatment had only a minimal effect on sulfur reduction.
Onset of ignition in solid fuels and modelling the natural convection

This thesis examines two important physical phenomena that occur when solid fuels are exposed to external radiative heating: (1) the pyrolysis process in reaching ignition conditions and (2) the natural convection around one or more radiatively heated fuel samples. A vegetation fire (bushfire, wildfire, or forest fire) preheating the vegetation which is in its path is a particular example which occurs in nature. However there are many more applications where modelling the pyrolysis process and/or the natural convection is of practical use.For the pyrolysis phenomena, a one-dimensional time dependent pyrolysis model is proposed. The mathematical model is solved numerically and results are used to analyse the influence of the size of a wood-based fuel sample, the heating rate it is exposed to, and its initial moisture content in the process of the sample reaching the conditions where it can produce enough pyrolysate vapour to support a flame (flash point). In many pyrolysis models in the open literature it is assumed that the fuel samples are dry. In the present study it is found that the initial moisture content has a marked effect for a fuel sample reaching its flash point.For the convection phenomena, a two-dimensional steady model, which explores the natural convection around one or more solid fuels, is also presented. The flame front is represented by a radiating panel. This means that the solid fuels receive a non-uniform heating rate depending on their geometry and location in relation to the panel. Changes in temperature and velocity profiles are monitored for varying heating rates and sample sizes (or, equivalently, the Rayleigh number Ra). Additionally, in the case of multiple fuel samples, changes in the distance between the fuels is also taken into account. For multiple fuels in arbitrary locations it is possible that one sample will block some of the radiation from the panel from reaching another sample. This means that the fuel sample will receive a reduced heating rate. This reduction in heating is also incorporated in the natural convection model.Both the pyrolysis and natural convection models are solved numerically using the finite element software package COMSOL Multiphysics. A comparison of COMSOL is performed with benchmark solutions provided by the open literature. A good agreement in the numerical results is observed.