Miracle-dz/UniFAR-FTUs huggingface dataset:
Optimization of fluoride adsorption onto a sonochemically synthesized nano-MgO/γ-Al2O3 composite adsorbent through applying the L16 Taguchi orthogonal design

AbstractHere in this work an effort has been made to in situ dope γ-Al2O3 as substrate with MgO nanoparticles through applying wet impregnation followed by sonochemical synthesis methods. The as-synthesized alumina supported nano-magnesia particles (4–30 nm) were evaluated as a new defluoridating agent upon operating conditions such as pH, initial concentration, contact time, temperature and sorbent dose. The L16 Taguchi statistical approach was implemented to optimize these operating conditions. The adsorbents were also characterized using the Fourier transform infrared spectroscopy, high resolution scanning electron microscope, X-ray diffraction and X-ray analysis methods. Under optimum conditions of pH 6.00 ± 0.30, initial concentration of 0.05 kg/m3, dose of 0.70 kg/m3, contact time of 8400 s and temperature of 298 K, the fluoride removal efficiency was up to 97%. Results of the ANOVA revealed that the most influential factor on the removal efficiency of nanoadsorbent would be the initial concentratio.
Dynamics of Internal Layers and Diffusive Interfaces

Internal layers: dynamics of internal layers Bistable fronts in an inhomogeneous medium Phase field models Flame theory: activation energy asymptotics for a one-step reaction Stability analysis of simple flames Flames due to chain branching Complex chemistry Electrophoresis: Models and problems Isotachophoresis Isoelectric focusing Waves in excitable and self-oscillatory media: One-dimensional problems Inhomogeneous media Curvature, corners, and twists Rotating waves.
A new transdermal drug delivery system containing hydroquinone

SUMMARY. Hydroquinone (HQ) is a drug reported to possess manifold biological activities. HQ is highly unstable into various topical vehicles, presenting low topical bioavailability and a relevant level of toxicity. The Pluronic® Lecithin Organogel (PLOme) is a phospholipidic microemulsion designed for transdermal purposes. The aim of this work was therefore to incorporate HQ into PLOme. We evaluated the stability, the kinetic profile and the antimicrobial activity of HQ- incorporated PLOme. No relevant pH variation was observed. Long-term stability test showed an HQ degradation which led to a short shelf life. HQ permeation rate obtained was lower from PLOme than from a gel matrix. Free and PLOme-encapsulated hydroquinone showed to have a great in vitro inhibitory potential against of S. aureus strains. The encapsulation of HQ due its unstable characteristics could be an alternative to optimize its therapeutic usage, and so further investigation is required on this pharmaceutical form before commercialization.
Production of protein- and carbohydrate-EPS in activated sludge reactors operated at different carbon to nitrogen ratios

BACKGROUND This study aimed to clarify how a variation in the carbon to nitrogen (C/N) ratio in influent wastewater affects the production and composition of extracellular polymeric substances (EPS) in activated sludge. In the literature such a comparative analysis is rarely presented, most studies on EPS focus on simultaneous organic carbon removal and nitrification whereas little attention is paid to the case of low organic load or separate-stage nitrification. RESULTS Among the very loosely bound, loosely bound and tightly bound EPS fractions, tightly bound EPS prevailed in semi-continuously fed batch activated sludge reactors that were fed at a C/N ratio of 10, 5 and 0, respectively. The C/N ratio had no clear effect on total EPS production, however it changed the proportion of proteins and carbohydrates. In each sludge proteins constituted the dominant part of EPS, but the EPS of the nitrifying sludge (C/N = 0), had a definitely higher protein content. As evidenced by HPSEC fingerprints, in all EPS fractions most proteins had MWs ≤16 kDa. Depending on the C/N ratio in a reactor, high MW proteins in EPS shifted from tightly bound fractions to others. CONCLUSION The study is among the few that highlight how the protein and carbohydrate content in EPS changes at different C/N ratios. Since wastewater composition in a treatment system affects the chemical composition of EPS, each sludge might have different responses to uptake of xenobiotics such as metals. Further, this difference in composition might affect sludge settling, dewatering and membrane fouling. © 2014 Society of Chemical Industry
Atomistic Simulations and Computations of Clay Minerals at Geologic Carbon Sequestration Conditions

Classical atomistic simulations are carried out to study carbon sequestration at deep underground formations. In classical simulations, formulas and equations are inherently different from those used in continuum and quantum calculations. Here, in contrast to continuum approaches such as the finite element method, interactions of atomic particles are computed, and unlike quantum techniques such as the density functional theory, calculations are not restricted to a limited number of atoms, therefore a balance between accuracy and computational cost makes classical atomistic techniques the best candidate to study layered materials in numerous situations. The success of CO2 sequestration depends on diverse parameters related to the depth and type of the underground formations. In this work, chemical, physical, and geometrical characteristics of formations are investigated. Different types of interlayer cation (Na+ and Ca2+), intercalated molecule (water and CO2), and clay structure (montmorillonite (MMT) and beidellite (BEI), and pyrophyllite (PPT)) are investigated as chemical parameters. Rotational degree of layers, pressure, temperature and chemical potential are considered as geometrical and physical variables. Using free energy calculations, stable energy states due to the intercalation of water and carbon dioxide to smectite structures are predicted. For hydrated systems, three states consisting of interlayer spacing values 9-10, 11.5-12.5 and 14.5-15.5 A, respectively called 0W, 1W and 2W hydration state are found. For systems including mixed H2O-CO2 intercalation, the amount of adsorbed CO2 alters and reaches its peak at the sub-first hydration levels. Another fascinating result emerges by simulating the binary MMT-CO2 system. The global minimum is found at the dry (0W) state which explains why there is no experimental observation of pure CO2 adsorption on the MMT surface. Finally, ternary smectite-H2O-CO2 simulations show that the amount of adsorbed CO2 in the clay phase is higher than that of bulk phase suggesting that the underground formation is a proper option to store extensive volumes of the green house gas carbon dioxide.
Adaptive two-scale models for processes with evolution of microstructures

In this dissertation two combinable numerical solution schemes are developed that - either in combination or on their own - allow for an efficient numerical solution of two-scale models that describe physical processes with changing microstructures via the combination of partial differential equations on a macro- and a microscopic length-scale. Furthermore, a two-scale phase-field model is established, that describes in a porous medium a pore-scale precipitation and a Darcy-scale diffusion process of in a fluid dissolved particles. One of the developed solution schemes is used in order to solve this model efficiently in a large time-space-cylinder. Numerical results show the interdependence of the pore-scale precipitation and the Darcy-scale diffusion process. In dieser Dissertation werden zwei effiziente numerische Losungsverfahren fur zweiskalige Modelle entwickelt. Durch die Kombination von partiellen Differentialgleichungen auf einer makro- und einer miskroskopischen Langenskala beschreiben die dabei betrachteten Modelle physikalische Prozesse bei denen die sich Mikrostruktur im Laufe der Zeit andert. Da die beiden Verfahren konsistent zueinander sind, garantiert ihre Kombination eine weitere Effizienzsteigerung. Des Weiteren wird ein zweiskaliges Phasenfeldmodell entwickelt, welches in einem poroen Medium auf der Mikroskala einen Ablagerungsprozess von in einem Fluid gelosten Partikeln und auf der Darcyskala deren Diffusion beschreibt. Zur effizienten numerischen Losung in einem grosen Raum-Zeit-Zylinder wird eines der beiden entwickelten Verfahren verwendet. Numerische Resultate belegen die gegenseitige Abhangigkeit des Ablagerungs- und des Diffusionsprozesses der gelosten Partikel.
Hybrid Clay/Porphyrin Nanomaterials for Oxygen Sensing

The presented research is focused on the investigation of hybrid systems of hosting clay minerals with incorporated metallated porphyrin molecules. These systems are used with intention to develop materials suitable for the construction of perspectively efficient oxygen sensors, as well as for the singlet oxygen pro-duction. As a guest materials, metalloporphyrins containing a heavy metals such as platinum and palladium are usually utilized. These are known to be very efficient for the oxygen sensing applications due to a “heavy atom effect”. This effect promotes a spin-orbit coupling, resulting in the fact that almost all of the radiation from singlet excited state undergoes the intersystem crossing, followed by a de-excitation via a triplet state. As a result, a phosphorescence from these systems can be observed in a presence of an inert gas, e.g. nitrogen. However, in a presence of a reactive oxygen the collisional quenching takes place, resulting in a diminish of phosphorescence. By changing the nitrogen-to-oxygen atmosphere and vice versa, one can study the behaviour of an “on-off” type sensing. It was found out that the clay/metalloporphyrin nanomaterials are perspective candidates for optical oxygen sensing applications.
Effect of water tension on ethylene production and consumption in montane and lowland soils in Austria

The trace gas ethylene affects plant growth and atmospheric chemistry and it interferes with soil restoration. In soil ethylene is simultaneously produced and consumed by different microorganisms. The effects of land use and soil moisture conditions on processes leading to an accumulation of ethylene are still unclear. We measured the rates at which montane and lowland soils from Austria produced and consumed ethylene over a range of water tensions and oxygen supply. Complete anaerobiosis (waterlogging, zero tension) favoured ethylene production, whereas ethylene degradation rates were greatest in soils at 30 kPa water tension. Soils from the lowland region of eastern Austria produced ethylene at rates of up to 12 pmol C2H4 g–1 h–1 under anaerobic conditions, and they consumed ethylene at rates reaching 231 pmol C2H4 g–1 h–1, after addition of 20 μl l–1 ethylene. Deciduous forest soils consumed ethylene fastest. Ethylene formed rapidly and was also consumed rapidly in soils rich in humus and total nitrogen. Soils taken from the mountains both produced and consumed ethylene more rapidly than lowland soils did. Production rates reached 146 pmol C2H4 g–1 h–1 under anaerobic conditions. Spruce forest soils produced significantly more ethylene than pastures. Ethylene formation was negatively correlated with soil pH. In montane soils ethylene production was related to the availability of simple carbon sources, expressed by the amount of extractable glucose equivalents. Maximum ethylene degradation amounted to 895 pmol g–1 h–1. Most of the soils were net sinks for ethylene at a water tension of 30 kPa and drier.
Estimation of net N mineralization from short‐term C evolution in a plant residue‐amended soil: is the accuracy of estimation time‐dependent?

Estimating N mineralization is important both environmentally and economically. Chemical and biological tests have been used for many years in an attempt to predict the N‐supplying capacity of soil. Simple methods are needed to predict N mineralization as a means to guide N management in rangeland ecosystems dependent on the natural N‐supplying capacity of soils. A short‐term C mineralization assay may provide a routine and rapid procedure to attain this goal. The objective of this study was to investigate the association of C and N mineralization in a calcareous soil. A calcareous soil was amended with eight range plant materials and incubated under aerobic condition (50% water holding capacity) at 25 °C. The potentially mineralizable C (C0) values ranged from 2232 mg C/kg soil with a decomposition rate constant (k) of 0.058/day for Hordeum bulbosum L. to 2834.2 mg C/kg soil with a k value of 0.115/day for Medicago sativa L. treatment. The k value for Medicago sativa L. treatment (0.115/day) was about two times greater than that of Hordeum bulbosum L. (0.058/day). The product of k and C0 (kC0) was highly correlated (r = 0.96, P < 0.001) with N mineralization/immobilisation (Nm). Moreover, Nm was more strongly correlated (r = 0.95, P < 0.001) with cumulative CO2‐C evolved during the first 6 days of incubation than other incubation periods. Overall, the quantities of Nm were closely associated with kC0 and short‐term CO2‐C evolution. The degree of association between C and N mineralization is time‐dependent.
Protein Folding Kinetics: Biophysical Methods

Structures of proteins. - Physical interactions that determine the properties of proteins. - Calculation of the kinetic rate constants. - High kinetic resolution of protein folding events. - Kinetic methods for slow reactions. - Resolution of protein structures in solution. - High structural resolution of transient protein conformations. - Experimental problems of the kinetic and structural resolution of reactions that involve proteins. - The folding pathway of a protein (barstar) at the resolution of individual residues from microseconds to seconds. - Highly resolved folding pathways and mechanisms of six proteins. - Structural determinants of the rate of protein folding. - Evolutionary computer programming of protein structure and folding. - Conclusions.
Mecanismos moleculares de la enfermedad de Alzheimer: Causas Genéticas y “esporádicas”

La enfermedad de Alzheimer (EA) es una enfermedad con un nivel de incidencia muy alto en lo que denominamos “primer mundo y que pasara a ser de relativa importancia en las sociedades en desarrollo ya que va asociada al envejecimiento de la poblacion. La prevalencia es o podra ser en breve, cercana al 20 % en la poblacion de la tercera edad. Tanto por los costes hospitalarios, como sociales, como familiares, es o sera un problema de primer nivel en las sociedades mas avanzadas. EA se caracteriza por un trastorno progresivo deterioro cognitivo y la personalidad que conduce a la demencia y la muerte. A nivel histopatologico, el cerebro del paciente AD muestra dos caracteristicas fundamentales que van asociadas en mayor o menor medida, las placas seniles y los ovillos neurofibrilares. Las placas seniles extracelulares estan formadas por proteina agregada denominada, amiloide, que puede estar rodeado por celulas de glia reactiva y por neuritas distroficas. Los ovillos neurofibrilares intracelulares, principalmente formados por la proteina tau anormalmente fosforilada o hiperfosforilada. Las actuales estrategias terapeuticas se basan en las drogas colinergicas, como donepezilo, rivastigmina y la galantamina y la memantina mientras se han presentado un grupo de terapias complementarias o alternativas que seran presentadas y discutidas. La actual busqueda de farmacos que sean eficaces es fundamental para una patologia que tiene estimaciones de la OMS de mas de 100 millones de personas en le mundo para el 2050. En el presente capitulo, vamos a revisar las bases de la patologia de origen genetico y la hipotesis del amiloide. Ademas presentaremos la dificultad de asignar un origen mas concreto a las variantes esporadicas que formalmente son mas del 90%. Discutiremos la seleccion y adecuacion de los modelos animales que se usan y que son fundamentales y condicionan la busqueda de nuevos farmacos.
Ab initio investigation of phase change materials : structural, electronic and kinetic properties

Phase change materials (PCMs) possess a peculiar combination of properties. They are capable of switching rapidly and reversibly between the amorphous and the crystalline phase at high temperature. However, the two phases are thermally very stable at room temperature. The pronounced optical and electrical contrast between these phases has enabled the development of data storage and memory technology based on PCMs. The investigation of PCMs is not only driven by the demands of industry, but also by the fundamental questions underlying these fascinating materials, which have drawn the attention of scientists and engineers during the past few decades. This thesis aims at providing an in-depth understanding of various aspects of PCMs at the atomic level by employing quantum mechanical simulations: density functional theory (DFT) and DFT based ab initio molecular dynamics (AIMD). The two methods are known as powerful tools in simulating real materials. After an introduction to PCMs and a review of the methodology, I start with the discussion of crystalline PCMs, in particular crystalline GeSbTe (c-GST) systems, where a significant amount of atomic disorder is detected. Recently, compelling evidence of disorder-induced localization of the electronic states has been found in c-GST experimentally. By atomistic modeling and electronic structure calculations, we have identified the microscopic origin of localization and we have proposed a plausible scenario for a disorder-order transition, which explains the metal-insulator transition (MIT) observed experimentally. All these findings provide important insights on controlling the wavefunction localization, which could lead to the development of multi-level data storage and other conceptually new devices based on multiple resistance states. In the second part, phase transformations between the amorphous and the crystalline state are investigated. The kinetic process of both amorphization and crystallization is modeled using AIMD. The structural properties of several amorphous PCMs are studied in detail. Chemical bonding in amorphous GeTe
Critical ranges of leaf micronutrient levels in coffee seedlings (Coffea arabica L.).

The objective of this work was to quantify the leaf micronutrient levels in coffee seedlings, to establish critical ranges in the experiment carried out in Federal University of Lavras, from May/2002 to January/2003. A random block design was arranged in a 6 x 4 factorial scheme (six fertilization levels and four sampling times), with four replications (nine plants were evaluated per plot). The evaluations were performed when the seedlings reached the stages of 3, 4, 5 and 6 pairs of leaves. The fertilization levels used were: 25%, 50%, 75%, 100%, 125%, and 150% with standard substrate). The following characteristics were evaluated: plant height, shoot diameter, leaf area, root dry weight, shoot and leaf dry weight's, and chemical analysis of the leaves to quantify the B, Cu, Fe, Mn, and Zn levels. To determine the critical ranges, the most adequate mathematical model to the fertilization levels in relation to plant performance was selected. For this purpose, where there was a significant effect of the fertilization level and of the interaction between time and fertilization level, regression analyses of each characteristic evaluated in each sampling time were performed. The same process was applied to the leaf micronutrient levels found in leaf dry weight, interpolated with the fertilization levels. Then the regression equations set for each characteristic in each sampling time were derived to determine the point of maximum performance. Using the equations it was possible to identify the ranges of the fertilization substrate levels that provided a maximum performance above 90% in the plants. These fertilization levels were substituted in the regression equations of the leaf micronutrient levels in each sampling time to find the critical range of micronutrients (mg/kg) : boron (39,74 to 39,94), copper (6,94 to 9,29), iron (209,01 to 213,88), manganese (33,05 to 37,21), zinc (3,68 to 4,08). The optimum stage to harvest leaves is four pairs of leaves.
Determination of ultra‐low oxygen concentrations in oxygen minimum zones by the STOX sensor

The methods used until now have not been able to reliably resolve O2 concentrations in oceanic oxygen minimum zones below 1–2 µmol L−1. We present a new amperometric sensor for the determination of ultra‐low O2 concentrations under in situ conditions. The electrochemical STOX O2 sensor contains a primary sensing cathode and a secondary cathode that, when polarized, prevents entry of O2 into the sensor. This arrangement enables frequent in situ zero calibration and confers the sensor with a detection limit of 1‐10 nmol L−1 O2, even during application on a Conductivity‐Temperature‐Depth (CTD) profiler at great water depths. The sensor was used during the Galathea 3 Expedition to demonstrate that the core of the oxygen minimum zone (OMZ) off Peru contained < 2 nM O2. Application in a reactor on board demonstrated that changes in O2 concentrations in OMZ water containing < 200 nmol L−1 O2 could be monitored over periods of hours to days. The linear decrease in O2 concentration in the reactor indicated very low (< 20 nmol L−1) half saturation constants for the O2 respiring microbial community.
A spectral survey of molecules in the Orion nebula from 455 - 507 GHz: an inventory of prebiotic chemistry

The results of a submillimetre wavelength spectral line survey between 455.1 - 507.4 GHz of the Orion-KL hot cloud core are reported. 254 lines were detected, and are associated with 30 different molecular species or their isotopomeric variants. Apart from the abundant diatomic rotors such as CO and CS, the spectrum is dominated by SO, SO2 and CH3OH and large organic molecules such as (CH3)(2)O, CH3CN, C2H3CN, C2H5CN and HCOOCH3 which make up similar to72% of the total number of lines; unidentified lines similar to13%; and other lines the remaining similar to15% of the total. Rotational temperatures and column densities derived using standard rotation diagram analysis techniques were found to range from 70 - 600 K, and 10(14) - 10(17) cm(2) respectively.
Synthesis and Characterization of Type II Silicon and Germanium Clathrates

Clathrate materials comprise compounds in which guest atoms or molecules can be encapsulated inside atomic cages formed by host framework polyhedra. The unique relationship that exists between the guest species and its host results in a wide range of physical phenomena, and offers the ability to study the physics of structure-property relationships in crystalline solids. Clathrates are actively being investigated in fields such as thermoelectrics, superconductivity, optoelectronics, and photovoltaics among others. The structural subset known as type II clathrates have been studied far less than other clathrates, and this forms the impetus for the present work. In particular, the known “composition space” of type II clathrates is small, thus the need for a better understanding of possible compositions is evident. A basic research investigation into the synthesis and characterization of silicon and germanium type II clathrates was performed using a range of synthetic, crystallographic, chemical, calorimetric, and transport measurement techniques. A series of framework substituted type II germanium clathrates has been synthesized for the first time, and transport measurements indicate that these compounds show metallic behavior. In the course of the investigation into type II germanium clathrates, a new zeolite-like framework compound with its corresponding novel crystal structure has been discovered and characterized. This compound can be described by the composition Na1-xGe3 (0 < x < 1), and corresponds to a new binary phase