Miracle-dz/UniFAR-FTUs huggingface dataset:
Using Nonparametric Optimal Transformations—Field Applications in the Middle East

Abstract Accurate prediction of formation fracture gradient is essential to many petroleum-engineering operations. Proper planning and execution of deep abnormal pressure wells, stimulation treatment, and reservoir exploitation require, among other factors, good estimates of fracture gradient. It has been proven in the literature that most of the available fracture gradient correlations do not provide reliable results when exposed to data away from the geographical region where they were initially developed. A new approach for fracture gradient prediction based on nonparametric optimal transformations is presented. The transformations are totally data driven and do not assume any a priori functional form. The model presents the fracture gradient as a function of pore pressure gradient, rock density, and depth. The data set used in the study consists of more than 21,000 points taken from 16 wells drilled in seven different geologic prospects covering more than 200 mi2. The excellent results obtained from the proposed model establish a new simple tool for fracture gradient calculation that is based on readily accessible parameters. The proposed model is illustrated and validated using several examples from different fields in the Middle East. The results of the various cases confirm that the computed and the measured fracture gradient values are in excellent agreement with an average absolute relative error of 6% and a standard deviation of 0.05 psi/ft.
Production and stable isotopic composition of CO 2 in a soil near Bern, Switzerland

During a period of one year, we measured the concentration and the stable isotopic composition of CO 2 in weekly soil air samples from two depths in a grass-covered soil. The CO 2 production rate, as estimated from the diffusion equation and the observed concentration gradient, was 15 mmol/m -2 /h -1 , as an annual mean. During the cold season, the production rate varied with soil temperature, but no correlation existed with temperature above about 10 °C. Concentrations and fluxes of N2O in the soil were also determined. Observed δ 13 C values were in the expected range, and δ 18 O of Soil CO 2 was found to be in isotopic equilibrium with the soil water. δ 18 O of the CO 2 released to the atmosphere is expected to be lower by roughly 8‰ due to diffusive isotope fractionation; the precise value depends on the competition between CO 2 production, equilibrium with soil water and diffusion. DOI: 10.1034/j.1600-0889.1991. 00013.x
Synthesis, characterization, and properties of new thermally curable polyetheresters containing benzoxazine moieties in the main chain

High molecular weight polyetheresters (PEE) containing thermally curable benzoxazine units in the main chain have been synthesized. For this purpose, first the diol functional monomer is synthesized through the Mannich reaction of 4,4′-isopropylidenediphenol (bisphenol A), formaldehyde, and 2-(2-aminoethoxy)ethanol. Polycondensation of the resulting benzoxazine dietherdiol with adipoyl chloride and terephthaloyl dichloride in the presence of triethyl amine yields the corresponding PEE with the molecular weights of 34.000 Da. The structures of the precursor diol monomer and the resulting PEEs are confirmed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy (1H-NMR) analysis. Curing behavior of both the monomer and polymers has also been studied by differential scanning calorimetry (DSC). Flexible free standing transparent films of the PEEs are obtained by solvent casting from dichloromethane solution on Teflon plates. The films preserve shape and, to some extent, toughness after thermal curing between 140 and 220 °C. Thermal properties of the cured polymers are also investigated by thermogravimetric analysis (TGA). © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 414–420, 2008
Polymerization in a system of discrete particles

It has been shown that subdivision of certain homogeneous polymerizing systems into droplets of diameter 10−4 to 10−5 cm. will entail a probability of finding only one active chain in each particle if the kinetics of the reaction remained otherwise unaffected. Some cases of polymerization in compartmentalized systems have been considered, and it has been shown that, where active centers are generated singly within completely isolated drops, the effect of increasing subdivision would be to increase the rate of reaction and chain length. On the other hand, with the formation of active chains in pairs, the opposite effect is to be anticipated, namely a decreasing rate of reaction with increasing subdivision. These conclusions are briefly considered in relation to the problem of dispersion polymerization, and it is shown that the theory of compartmentalization could account for the occurrence of high rates of reaction and chain lengths in the emulsion process, as compared with a bulk system. On the other hand, there is no evidence showing that the reaction rate is ever reduced in finely dispersed systems.
Managing soil organic matter – implications for soil structure on organic farms

Abstract. This paper reviews current understanding of soil structure, the role of soil organic matter (SOM) in soil structure and evidence for or against better soil physical condition under organic farming. It also includes new data from farm case studies in the UK. Young SOM is especially important for soil structural development, improving ephemeral stability through fungal hyphae, extracellular polysaccharides, etc. Thus, to achieve aggregate stability and the advantages that this conveys, frequent input of fresh organic matter is required. Practices that add organic material are routinely a feature of organically farmed soils and the literature generally shows that, comparing like with like, organic farms had at least as good and sometimes better soil structure than conventionally managed farms. Our case studies confirmed this. In the reviewed papers, SOM was generally larger on the biodynamic/organic farms because of the organic additions and/or leys in the rotation. We can therefore hypothesize that, because it is especially the light fraction of SOM that is involved in soil structural development, soil structure will improve in a soil to which fresh organic residues are added regularly. Thus, we argue it is not the farming system per se that is important in promoting better physical condition, but the amount and quality of organic matter returned to a soil.
Boron nitride phase diagram. State of the art

Abstract From recent experimental data on BN thermodynamic propeties, the equilibrium phase diagram for boron nitride has been plotted, which differs from the generally accepted Bundy-Wentorfs one. At atmospheric pressure cubic boron niride has been shown to be a thermodynamically stable modification up to temperatures of 1600 K, which drastically changes the established notions of BN polymorphism, based on assumed analogy of phase diagrams for carbon and boron nitride. These studies have shown that according to the proposed equilibrium phase diagram the threshold pressure of cBN crystallization can be reduced from 4 down to 2 GPa with the supercritical fluids present, which opens new fields for developing methods for cBN low-pressure synthesis.
EFFECT OF QUNINE IN HEPATOTOXICITY AND KIDNEY FUNCTION IN MALE RAT

The present study was designed to evaluate its effects of Quinine on body weight and its hepato-nephrotoxicity. Twenty mice were randomly divided into four different groups of five animals in each group, (600 mg/Kg, 650 mg/Kg, 700 mg/Kg and control) groups. The treatments were administered for two weeks. Quinine produces a significant increase in the mean values of body weights and aspartate and alanine aminotransferase, alkaline phosphatase and a total bilirubin level of treated mice of 700mg/kg group compared with the animals in the control group, compared with a control group. Key Ward: Quinine, liver, kidney, toxicity.
Effects of inorganic speciation on the interpretation of copper adsorption by soils

SUMMARY A previous study with a range of soils indicated that adsorption of copper could not be adequately described by the Freundlich equation. Adsorption curves for all but a highly calcareous soil could be divided into two straight lines with a marked increase in slope at low solution concentrations. A computer program (QELIOS) has now been used to calculate the effects of pH, CO, partial pressure and different inorganic anions on the chemical equilibria of the systems used in the adsorption experiments. At pH 6–8.5, hydrolysed species play a major role in Cu speciation whereas CO2−3 species become important only at pH > 8.0. The sensitivity of Cu hydrolysis to pH changes and to total Cu concentration in solution provides a possible explanation for the two surface Freundlich curves for soils of pH 6–7, and for the lack of such double surfaces for soils of pH > 7.
Improving Student Attitudes about Science by Integrating Research into the Introductory Chemistry Laboratory:: Interdisciplinary Drinking Water Analysis

The integration of student research into a general chemistry laboratory and an environmental geology course has been evaluated for its effectiveness to improve (i) student attitudes about science and chemistry, (ii) student understanding of the nature of experimental science and the scientific method, and (iii) student perceptions of the application of science and the interdisciplinary nature of science. Students in introductory science courses frequently devote all or most of their time and effort to learning basic laboratory techniques by following predefined procedures that have intentionally predictable outcomes. Though this longstanding model of laboratory structure is an important means of effectively preparing students for future chemical study, it often neglects items i−iii. Students were guided through a research experience by an interdisciplinary team of faculty so that students could begin the research and bring it to an appropriate conclusion, including formal presentations, within a single se.
The Thiol-Michael Addition Click Reaction: A Powerful and Widely Used Tool in Materials Chemistry

The key attribute of the thiol-Michael addition reaction that makes it a prized tool in materials science is its modular “click” nature, which allows for the implementation of this highly efficient, “green” reaction in applications that vary from small molecule synthesis to in situ polymer modifications in biological systems to the surface functionalization of material coatings. Over the past few decades, interest in the thiol-Michael addition reaction has increased dramatically, as is evidenced by the number of studies that have been dedicated to elucidating different aspects of the reaction that range from an in-depth analysis aimed at understanding the mechanistic pathways of the reaction to synthetic studies that have examined modifying molecular structures with the aim of yielding highly efficient thiol-Michael reaction monomers. This review examines the reaction mechanisms, the substrates and catalysts used in the reaction, and the subsequent implementation of the thiol-Michael reaction in materials.
Raman spectroscopy of phosphates of the variscite mineral group

Raman spectra of phosphates of the variscite mineral group, namely strengite, variscite, metavariscite and phosphosiderite, were obtained at 298 and 77 K using a thermal stage and complemented with selected infrared data using a diamond attenuated total reflection cell. Multiple phosphate stretching bands are observed. Bands for strengite at 1006, 1012 and 1026 cm-1 at 298 K and at 997, 1006, 1014 and 1027 cm-1 at 77 K are observed. Variscite is characterized by PO stretching vibrations at 1023, 1005 and 938 cm-1 and phosphosiderite by bands at 1009 and 993 cm-1. These minerals are readily identified by their Raman spectrum both in the PO stretching region and in the low-wavenumber region. Multiple bands attributed to the bending modes of PO4 are identified for each of the minerals. A model is proposed involving non-hydrogen-bonded PO4 and strongly hydrogen-bonded PO4 units together with [Al or Fe(OH)2]+ ·(H2PO4)2--type species. Raman spectroscopy shows that at the molecular level multiple species of phosphate anions exist for the variscite phosphate minerals.
Digital simulation of industrial steam reformers for natural gas using heterogeneous models

A model is developed for industrial natural gas steam reformers with top-fired and side-fired furnance design. The one-dimensional heterogeneous model for catalyst tubes takes into account the intra-particle diffusion resistances. Two approximations are used for the computation of the effective diffusivities via the Stefan-Maxwell equations. The two-point boundary value differential equations for the catalyst pellets are solved by a novel efficient and modified orthogonal collocation technique. The performance of the model has been checked in the case of two industrial reformers used in the ammonia and methanol industries in Egypt and Saudi Arabia. On a mis au point un modale pour des reformeurs industriels a la vapeur et au gaz naturel dont la conception du four prevoit une alimentation dans la partie superieure du reformeur ou la partie laterale. Le modele heterogene unidimensionnel pour des tubes de catalyseur tient compte des resistances de diffusion intraparticulaire. Deux approximations sont utilisees pour le calcul des diffusivites efficaces via les equations de Stefan-Maxwell. Les equations differentielles de la valeur limite a deux-points pour les pastilles de catalyseur sont resolues par une nouvelle technique de collocation orthogonale efficace modifiee. On a verifie la performance du modele dans le cas de deux reformeurs industriels utilises dans les industries de l'ammoniac et du methanol en Egypte et en Arabie Saoudite.
Decolourisation of Orange II by a Wood-Rotting Fungus

The decolourisation of Orange II by a wood-rotting fungus has been studied. It was found that Fungus F29 could effectively decolourise Orange II especially when grown as pelleted mycelia under agitated conditions. Many factors affecting the decolourisation process in nitrogen-limited media (NLM) were studied, including: concentration of glucose, NH4+, Mn(II) and veratryl alcohol; initial pH; amount of mycelium; mycelial age; Orange II concentration; temperature. Results showed that the media containing Orange II at 1000 mg dm−3 (or higher) could be decolourised by 98% of the initial colour (A480 nm) in 2 days, in most conditions tested, and that the mycelia could be repeatedly reused. © 1997 SCI.
VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data

VESTA is a three-dimensional visualization system for crystallographic studies and electronic state calculations. It has been upgraded to the latest version, VESTA 3, implementing new features including drawing the external mor­phology of crystals; superimposing multiple structural models, volumetric data and crystal faces; calculation of electron and nuclear densities from structure parameters; calculation of Patterson functions from structure parameters or volumetric data; integration of electron and nuclear densities by Voronoi tessellation; visualization of isosurfaces with multiple levels; determination of the best plane for selected atoms; an extended bond-search algorithm to enable more sophisticated searches in complex molecules and cage-like structures; undo and redo in graphical user interface operations; and significant performance improvements in rendering isosurfaces and calculating slices.
NIRvP: a robust structural proxy for sun-induced chlorophyll fluorescence and photosynthesis across scales

Max Planck Institute for Biogeochemistry, Hans Knoll Straße, 10, D-07745 Jena, Germany International Institute for Earth System Sciences, Nanjing University, Nanjing, Jiangsu 210023, China. Jiangsu Provincial Key Laboratory of Geographic Information Technology, Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural Resources, School of Geography and Ocean Science, Nanjing University, Nanjing, Jiangsu 210023, China.
PHYTOCHEMICAL SCREENING AND IN-VITRO ANTIOXIDANT ACTIVITY ON VERNONIA AMYGDALINA (EWURO- BITTER LEAF)

Most of the plants exhibit a variety of phyto-pharmaceuticals, which have important applications in the fields of agriculture, human and veterinary medicine. This study was conducted to evaluate phytochemical screening and in-vitro antioxidant activity on Vernonia amygdalina (bitter leaf) at the Department of Biological Sciences, Federal Polytechnic, Ado Ekiti. It was revealed that the phytochemical constituents in Bitter leaf (Vernonia amygdalina) were alkaloids, saponin, tannins, terpenoids, flavonoids and cardiac glycosides in the extract. Anti-oxidant property results of the aqueous extract of Bitter leaf (Vernonia amygdalina) showed Total phenolic content was 120.16mg Gallic acid equivalent/g extract while the total flavonoid was 235.147mg Quercetin equivalent/g extract. The plant could be exploited as source of antioxidant additives and used for future project to evaluate the potentials of Bitter leaf (Vernonia amygdalina) as a strong medicinal plant in improving human health status.
Waxy Crude Oil Emulsion Gel: Impact on Flow Assurance†

In oilfield operations, the formation of crude oil emulsions is very common and can cause significant flow assurance problems during oil production. These emulsions can be very stable as a result of the presence of polar compounds, such as asphaltenes and resins, that play the role of natural surfactants and also because of the occurrence of many types of fine solids that can form resistant films at the crude oil/water interface. Gelled waxy crude oil flows have been largely studied, and the effect of dispersed water on crude oil rheology has been well-characterized; however, little attention has been given to the potential impact of waxy crude oil emulsion gel formation. In this study, it is shown that in some waxy crude oils the presence of water above a threshold value could promote gel formation, significantly changing the viscosity of the mixture. The rheological properties of waxy crude oils were determined at different water cuts, temperatures, and shear rates, and also a chemical characterization .
Chromium(IV) Stabilisation in New Ceramic Matrices by Coprecipitation Method: Application as Ceramic Pigments

In this paper the stabilization of Cr4+ in new ceramic matrices as willemite Zn2SiO4 and galium-gadolinium garnet GGG (Gd3Ga5O12) is studied and compared with the chromium-sphene ceramic pigment using the traditional solid reaction and an unconventional coprecipitation method.The chromate amount etched from the powders using CrIII and CrVI precursors on ceramic and coprecipitation routes are analysed in order to evaluate the environmental impact on the waste water. Cr-willemite and codoped Ca, Cr-GGG produces solid solutions of Cr4+ ion occupying tetrahedral and dodecahedral sites, respectively, while Cr4+ into sphene lattice occupies octahedral sites. Cr-willemite are stable when used as ceramic pigment in habitual tile glazes but Cr-GGG unstabilses and produces green colour associated to Cr3+ solved in the glaze. Coprecipitate powders are more reactive than ceramic powders but in Cr-GGG stabilizes the metastable Ca3Cr2O8 oxide. Chromate amount in washing hot water are not dependent of the chromium precursor but depends of the allowed reactivity level and the reaction media.
Kinetic and equilibrium studies of simultaneous adsorption of monochlorophenols and chlorophenoxy herbicides on activated carbon

AbstractAdsorption on activated carbon is one of the well-established and effective techniques for the removal of chloroorganic pollutants from surface water, groundwater, and drinking water. Since these water contaminants occur often together in the present study, kinetics and equilibria of simultaneous adsorption of selected chlorophenols and chlorophenoxy herbicides from aqueous solutions are investigated and described. For investigations, three monochlorophenols (2-chlorophenol, 3-chlorophenol, and 4-chlorophenol), as well as chlorophenoxy hebicides (2,4-dichlorophenoxyacetic acid and 2-methyl-4-chlorophenoxyacetic acid), are chosen. As adsorbent granular-activated carbon Filtrasorb 300 (938 m2/g) was used. Adsorption quantities were determined by HPLC method. Kinetics of adsorption was described by pseudo-second-order model and adsorption equilibria by Freundlich equation. Proposed method can be used for adsorption from multicomponent aqueous solutions.
A molecular dynamics study of the thermodynamic properties of barium zirconate

In this paper, a molecular dynamics (MD) simulation is carried out to study the microscopic atomic behavior and the macroscopic thermodynamic and thermal transport properties of a perovskite material. A new set of potential parameters is presented for barium zirconate. The radial distribution function is estimated to understand the atomic and structural behavior. The variation of lattice parameters, thermal expansion coefficient, isothermal compressibility, heat capacity and thermal conductivity are evaluated in the temperature range 298–2000 K and the pressure range 1 atm–20.3 GPa. The thermal conductivity calculation is performed using the non-equilibrium MD method, and a correction for the finite size effects is made. The simulation results show good agreement with the experimental findings.
Behavioural Immune System responses to coronavirus: a Reinforcement Sensitivity Theory explanation of conformity, warmth towards others and attitudes towards lockdown

The outbreak and rapid spread of the Coronavirus (COVID-19) has presented critical challenges for individuals and society. Worldwide, governments have imposed lifestyle restrictions, limiting physical contact between people in an attempt to slow the rate of infection. This study investigated how a perceived vulnerability to disease can affect conformity to social normative behaviours, attitudes towards other people and attitudes towards the lockdown measures. We tested 600 member of the UK public during the time when the most stringent lockdown measures were in place. Our results showed that behaviours and attitudes were driven by more than fear of infection. Personality traits related to a drive to achieve social goals and experience the social rewards of interaction partially explained conformity and attitudes towards other people. Importantly, our results showed that the level of behavioural information presented in most government communications is appropriate to activate a perception of vulnerability and to trigger preventive lockdown compliant behaviours. This study presents new insights into public perceptions of coronavirus and government regulated lifestyle restrictions, helping to explain social behaviours in terms of biologically driven mechanisms. Such understanding is vital if we are to successfully motivate public behaviour to constrain spread of the virus.