Miracle-dz/UniFAR-FTUs huggingface dataset:
Structure and properties of clay nano‐biocomposites based on poly(lactic acid) plasticized with polyadipates

The use of nano-biocomposites based on plasticized poly(lactic acid) (PLA) has been proposed as a way to improve the polymer ductility and to expand PLA applications window. Novative nano-biocomposites were elaborated with PLA plasticized by polyadipates (15 wt%) with different molar masses (from 1500 to 2500 Da), with 2.1 wt% of an organo-modified montmorillonite (O-MMT). These materials showed enhanced ductility and barrier properties. The clay was swelled in liquid polyadipates prior to their blending with PLA to facilitate chains intercalation and nanofiller exfoliation during melt-blending. In certain processing conditions, quite homogenous and exfoliated structures were obtained, as shown by X-ray diffraction (XRD) and transmission electronic microscopy (TEM) results. Irrespective of the average molar mass of the polyadipate, the clay addition induced a reduction in around 25% in oxygen transmission rate (OTR) without an important detriment in tensile properties. Nano-biocomposites prepared with higher molar masses polyadipates showed the highest thermal stability as well as the lowest OTR, resulting in very promising and novative materials for different applications such as soft packaging. Copyright © 2010 John Wiley & Sons, Ltd.
The relationship between stock market volatility and economic activity

This thesis investigates the empirical relationship between stock market volatility and economic activity in the US, the UK, Finland, Sweden and Germany with a sample from January 1990 to November 2019. Stock market volatility is measured using generalised autoregressive conditional heteroskedasticity (GARCH) models and economic activity is proxied by the industrial production growth. First, bivariate VAR models are fitted to analyse this relationship in each country individually. Further, multivariate VAR analysis is conducted to analyse the interconnectedness of the markets. Linear causality tests are employed to analyse the full sample, as well as the effects of the financial crisis of 2008 by splitting the sample into preand post-sample periods. The results suggest several bidirectional causal relationships as well as unidirectional ones. The relationships become more significant in the post-crisis sample, indicating a structural break in the data. Finally, the US is found to have a substantial impact on the other markets.
MODELING OF NOx EMISSIONS FROM FLUIDIZED BED COMBUSTION OF HIGH VOLATILE LIGNITES

A comprehensive model, previously developed and tested for prediction of behavior of continuous fluidized bed combustors is extended to incorporate NOx formation and reduction reactions and applied to the simulation of Middle East Technical University (METU) 0.3 MWt Atmospheric Bubbling Fluidized Bed Combustor (ABFBC) burning lignites with high Volatile Matter/Fixed Carbon (VM/FC) ratios in their own ashes. Favorable comparisons are obtained between the predicted and measured temperatures and concentrations of gaseous species along the combustor. Results show that determination of partitioning of coal nitrogen into char-N and volatile-N, char combustion rate, and amount of volatile nitrogen released along the combustor are found to be the most important parameters that affect NO formation and reduction in bubbling fluidized bed combustors.
CFD and experimental study on methane hydrate dissociation. Part II. General cases

Rate equations proposed in Part I were extended to dissociation processes induced by different methods such as depressurization, raised temperature, or simultaneous changes in temperature and pressure. For all cases, the dissociation rate of hydrate into the two-phase coexisting region (V-LW) can be expressed by a general form of the product of the rate constant and the logarithm of the solubility ratio of methane in the aqueous solution, xR to xS: xR is the solubility of methane in the aqueous solution that is hypothetically in equilibrium with the hydrate phase under the dissociation pressure and temperature, and xS is the equilibrium solubility of methane in water under the same dissociation condition. The virtual solubility of methane, xR, can be estimated by extrapolating the solubility curve of methane under the conditions in equilibrium with the stable hydrate to the region at which the dissociation occurs by a simple thermodynamic treatment. The dissociation equation was applied to experimental results of dissociation processes induced by depressurization with methane bubble formation. The experimentally observed dissociation rates were well correlated by the rate equation with the dissociation constants determined in Part I. The results suggest that the dissociation equation can be applied generally to dissociation processes that occur by different methods, and the rate constant is a universal parameter within the experimental range examined in this work. © 2007 American Institute of Chemical Engineers AIChE J, 2007.
Heterogeneous cracking of wood pyrolysis tars over fresh wood char surfaces

Char-induced conversion of newly formed wood pyrolysis tars was measured for independent variations in temperature and tar-char space time. Tar vapors were generated by controlled devolatilization of shallow (∼2 cm deep) packed beds of 45-250 μm particles of sweet gum hardwood. Heterogeneous conversion was significant but essentially constant at 14±7 wt% of tar (to 2 standard deviations), for temperatures from 400 to 600 o C and space times from 2.5 to 100 ms. In contrast, vapor-phase tar conversion upstream of the char bed ranged from 0% at 400 o C to 30% (wt% of vapor-phase tar conversion upstream of the char bed ranged from 0% at 400 o C to 30% (wt% of tar) at 600 o C. The implication is that an otherwise thermally stable fraction of newly formed wood pyrolysis tars is very reactive in the presence of wood char
Construction and Testing of a Durable Platinum Wire Eh Electrode for In Situ Redox Measurements in the Subsurface

We have developed a rugged, durable platinum wire Eh electrode for application in subsurface environments. The electrode design is described in detail and its performance under aerobic and anaerobic steady‐state and transient conditions is assessed. The electrode consists of a 0.5‐mm‐diameter platinum wire (99.99% purity) cast in a glass fiber‐reinforced epoxy jacket. The construction allowed installation through direct insertion into sandy media to depths up to several meters. Data collection was through connection to a datalogger with high impedance input; data points were collected every 10 seconds and averaged and stored once an hour. The electrodes functioned in situ for periods of more than three years and gave reliable readings during oxic, anoxic, and transitional conditions. Performance testing and examination of electrodes recovered after three years in situ indicated that they were not impacted by corrosion, dissolution, or poisoning.
Superior elastomeric nanocomposites with electrospun nanofibers and nanoparticles of CoFe2O4 for magnetorheological applications

We show for the first time the greatly enhanced magnetic and magnetorheological (MR) properties of CoFe2O4–silicone elastomer (cross-linked polydimethylsiloxane) composites containing electrospun CoFe2O4 nanofibers. The effects of CoFe2O4 particle shape (spherical to fibrous), concentration and degree of alignment in the elastomeric matrix are explored. Low nanofiber loadings (5–10 wt%) give MR properties comparable to those obtained by much higher microparticle additions (60–80 wt%) for the same polymer matrix. Compared to spherical nanoparticles, the nanofiber composites have 100–400% improvement in MR properties that are vital in tunable rheology applications such as vibration damping, variable stiffness devices, actuators, etc. The nanofibers effectively formed an interconnected network within the polymer matrix but nanoparticles exhibited large gaps between two disconnected short particle chains at lower filler loading. Spherical particles with 69.46 emu g−1 saturation magnetization were synthesized by ultrasonic assisted co-precipitation method using a novel precipitating solvent (i.e. propylamine) followed by calcination. The nanofibers were prepared by electrospinning a precursor of CoFe2O4 in a sacrificial polymer solution of polyvinylpyrrolydone (PVP) followed by calcination of electrospun fibers. Crystal structure and magnetic properties of the CoFe2O4 nanofillers were evaluated by X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometery (VSM), which showed the generation of larger crystallite size with greater coercivity and remnant magnetization in the nanofibers compared to nanoparticles. Thin films of the nanocomposites containing nanoparticles and nanofibers were prepared with 5 and 10 wt% of CoFe2O4. Anisotropic characteristics of the nanocomposites were generated by applying an in situ magnetic field of 0.4 T during solution casting of thin composite films. The magnetorheological study revealed that at 1.023 T, the isotropic nanocomposites with 10 wt% nanofibers showed absolute and relative MR effects of 4.4 kPa and 3.21%, respectively, compared to the corresponding nanoparticle containing counterpart's values of 2.0 kPa and 0.64%.
SIMPLE DETERMINATION OF ERDOSTEINE IN HUMAN PLASMA USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

A simple and rapid high-performance liquid chromatography (HPLC) method with UV detection (220 nm) was developed for the determination of erdosteine in human plasma. The plasma was prepared by deproteination based on treatment with 6.25% trichloroacetic acid (TCA). After the mixture was centrifuged, the supernatant was separated on CAPCELL PACK C18(4.6 × 250 mm) column. The mobile phase consisted of acetonitrile in phosphate-heptane sulfonate buffer at the volume ration of 5:95 (pH 2.0). Citiolone was used as an internal standard. The calibration curve was linear in concentrations of 0.5–8 μg/mL with correlation coefficient of 0.999. The limit of quantitation (LOQ) was 0.5 μg/mL. This method was sensitive with reproducibility and specificity and successfully applied to the bioequivalence study of erdosteine (900 mg) in healthy subjects.
Thermal Expansion of Delta and Epsilon Zirconium Hydrides

The thermal expansion characteristics of polycrystalline delta (face‐centered‐cubic) zirconium hydride and epsilon (body‐centered‐tetragonal) zirconium hydride were determined between room temperature and 362°C and 300°C, respectively, by means of x‐ray diffraction techniques. The average linear thermal expansion coefficient for the delta phase is 2.98×10—6/°C for the range 24° to 362°C. For the epsilon phase, the average coefficients for the range 24° to 300°C are —1.4×10—6/°C and 30.6×10—6/°C for the a and c directions, respectively, and 9.3×10—6/°C for the randomly oriented polycrystalline material.
Morphology of n-alkanes, linear polyethylene, and isotactic polypropylene crystallized from solution†

The morphology of two n-alkanes (n-C44H90 and n-C82H166, prepared by E. Stenhagen, et al. ) and linear polyethylenes (Ziegler-type of low and Marlex 50 of high molecular weight, respectively), crystallized from dilute solution by slow cooling, have been studied by electron microscopy and small-angle x-ray scattering. A series of solvents were used with cloud points for polyethylene from about 120°C. (poor solvents, e.g., diphenyl ether) to 65–75°C. (good solvents, e.g., tetrachloroethylene). All samples crystallized with basically the same morphology, showing large, thin flakes or lamellac with the chains perpendicular to the plane of the flakes. This involves chain folding for all polyethylenes studied, as proposed by Keller. In most cases, the large flakes were overgrown with or accompanied by diamond- or lozenge-shaped single crystals (as reported by Jaccodine and Till) containing from 2 to about 20 lamellae and developed as pyramids, sometimes as spirals and sometimes as consecutive layers. Isotactic polypropylene crystallized with a similar morphology. The nucleation and growth mechanisms of the large flakes are not clear. They seem to grow without dislocations, while the diamond-shaped crystals seem to form according to Frank's screw-dislocation growth concepts. Crystallization of polyethylene at high temperatures give thicker lamellae (165 A. at 120°C.) than crystallization at low temperatures (103 A. at 60°C.), as measured by small-angle x-ray scattering, regardless of molecular weight. When heated, the lamellae recrystallized to larger thickness. This would imply that the folding length of the polyethylene chains and the related thickness of stable lamellae are primarily a function of the crystallization temperature. The lamellae of n-alkanes showed a thickness which agreed with the extended chain length of each sample within a few angstroms.
An Improved One-Pot Synthesis of Dimethyl Carbonate from Propylene Oxide, CO2 and Methanol

The direct synthesis of dimethyl carbonate (DMC) and propylene glycol from propylene oxide, CO2 and methanol has been studied with potassium carbonate as catalyst. This is the first time that K2CO3 which is readily available has been used as a catalyst. It is quite simple and cheap to use. This route may be an effective way of producing DMC on the large-scale. DMC is used in polycarbonate synthesis, polyurethane synthesis, carbonylating reagents, alkylating reagents, polar solvents, octane boosters in gasoline, carbon-particle reducing agents for diesel engines It is a safe and environmentally benign alternative for phosgene in some reactions.
Preservation and Storage of Water Samples

Starting from the sampling up to the time of analysis, the content of water sample can be altered due to the chemical, physical, and biological reactions it undergoes. This article deals with the processes occurring in the water samples during their storage and with reasons of their occurrence. Special attention has been paid to the chemical and physicochemical reactions as well as to microbiological and photochemical degradation of the component of the sample. Techniques for the water sample preservation are also reviewed.
INFLUENCE OF AERATION RATE AND LIQUID TEMPERATURE ON AMMONIA EMISSION RATE AND MANURE DEGRADATION IN BATCH AEROBIC TREATMENT

The influence of aeration rates (26, 63, and 100 .g O2 g VS-1 min-1) at different temperatures (5°C, 15°C, and 25°C) on ammonia emission and breakdown of organic materials was studied using 15.3 L batch reactors for 21 days. The removal of total Kjeldahl nitrogen (TKN) ranged from 9.7% to 37.7% during the experiment, with higher values corresponding to higher manure temperatures and aeration rates. Ammonia loss ranged from 0.7% to 25.8% of initial TKN and increased with increase in manure temperature and aeration rate. In a similar pattern, the ratio of volatilized ammonia gas to removed TKN varied from 6.5 to 68.5. In addition, high BOD5 removal was also observed when both the temperature and the aeration rate were high, with the exception for airflow rates between 26 and 63 . g O2 g VS-1 min-1 for the manure at temperatures between 5°C and 15°C. The combinations of high aeration rate (100 .g O2 g VS-1 min-1) with low temperature (5°C) or low aeration rate (26 .g O2 g VS-1 min-1) with high temperature (15°C to 25°C) were found to be desirable to reduce ammonia emission while still achieving satisfactory BOD5 removal at the same time.
Metabolic profiling and discrimination of two cacti cultivated in Korea using HPLC-ESI-MS and multivariate statistical analysis

Metabolic profiling of cactus samples collected on Jeju Island (Opuntia ficus-indica) and in Sinan, Jeonnam province (O. Humifusa) was carried out using high performance liquid chromatography-electrospray ionization mass spectroscopy (HPLC-ESI-MS) and multivariate statistical analysis. The samples were classified into two characteristic groups and the flavonoid glycosides accounting for the observed variations were identified by MS/MS analysis. This approach provided an overview of the differences among plant products originating from differences in the genetic nature of plants.
ADSORPTION OF SOME NITROGENATED HERBICIDES BY SOIL HUMIC ACIDS

We studied the adsorption of two s-triazine and two substituted urea herbicides by three different soil humic acids, using elementary analyses and infrared spectroscopy. Obtained data show that adsorption occurs in all cases, involving such mechanisms as ionic bonds, only for the s-triazines; H-bonding; van der Waals forces; and possibly charge transfer in both s-triazine-HA and substituted urea-HA complexes. The extent of adsorption is higher for s-triazines than for substituted ureas, in the order: prometone > methoprotryne > monuron > fenuron.
Statistical Evaluation of Factors Affecting Indicator Bacteria in Urban Storm-Water Runoff

An urban watershed in Raleigh, North Carolina, was monitored for indicator bacteria during 20 rain events. Results showed elevated levels of E. coli, enterococci, and fecal coliform. Samples were compared based on seasonality and were found to be statistically different ( p<0.05 ) , with pairwise comparisons indicating significantly lower concentrations of E. coli and fecal coliform during the winter ( p<0.05 ) . Enterococci concentrations were substantially lower in the winter and fall, but no significant differences were found between seasons during pairwise comparisons ( p<0.05 ) . Correlation analyses showed multiple significant relationships between antecedent climate parameters, flow characteristics, and indicator bacteria concentrations. More detailed multiple linear regression yielded explanatory variables related to antecedent climate conditions. Variables were generally related to temperature and moisture conditions in the atmosphere and soil. The results of this study show indicator bacteria co.
Molecular Weight Distributions of Organic Halogens In Bleached Kraft Pulp Mill Effluents

The molecular weight distribution of chlorinated compounds of bleached kraft mill effluent (BKME) was studied by aqueous and nonaqueous size exclusion chromatography (SEC) and by ultrafiltration. Ninety percent of the BKME halogenated organics dissolved into tetrahydrofuran used as a nonaqueous SEC eluent. The tetrahydrofuran-soluble component of the BKME had the the molecular weight distribution as the original BKME when both were analyzed by aqueous SEC. Over 85% of the chlorinated material of BKMEs studied by nonaqueous SEC was of low molecular mass (<1000 g/mol).
Preparation of Main-Chain Thermotropic Polyesters With Two Types of Mesogens Connected Alternatively by Aliphatic Spacers

A homologous series of main-chain thermotropic polyesters (PBTn, n = 2, 4, 6) containing biphenyl and triad aromatic ester mesogenic units interconnected by n-methylene spacers in the main chain were prepared from terephthaloyl bis(4-oxybenzoyl chloride) (TOBC) and 4,4′-bis(ω-hydroxyalkyloxy)biphenyls (n-BP, n = 2, 4, 6) by solution polycondensation. The chemical structures of the monomers and PBTn were characterized by spectroscopic techniques and elemental analysis. The solubility, supermolecular structures, thermal and liquid crystalline properties of PBTn were investigated by differential scanning calorimetry (DSC), polarizing microscopy (PLM), small-angle X-ray scattering (SAXS), thermogravimetric analyses (TGA), and wide-angle X-ray diffraction (WAXD), and they were found to be closely dependent on the length of the methylene spacers. The increasing methylene units led to improved solubility, broader liquid crystalline range, reduced mesophase-isotropic transition point, higher thermal stability, and decreasing crystallinity. The decomposition temperatures (5% mass loss) of the polymers were above 380°C in nitrogen atmosphere and only PBT4 and PBT6 exhibited smectic mesophases as well as high viscosity in the mesophase.
THE EFFECT OF PROCESSING ON THE NUTRIENT CONTENT OF CASSAVA (MANIHOT ESCULENTA CRANTZ) LEAVES

Leaves of two varieties of cassava (Manihot esculenta Crantz) – TME1 (local) and TMS30572 (improved) – were subjected to African household processing (heat-treated, pounded and cooked and crushed, ground and cooked) and compared for proximate composition, minerals, vitamins and antinutritional factors. The processing methods had no effect on ash, lipids, protein, fiber, total carbohydrate, carotene, calcium, magnesium, potassium, sodium, phosphorus, copper, zinc and manganese but produced diminution in free sugars (23.2% reduction), ascorbic acid (77.7% reduction), thiamine (37.1% reduction), cyanogenic potential (>99% reduction) and tannin (55.2% reduction;) levels. On the contrary, iron level increased three- to fivefold with grinding but not with the pounding process. This study showed that adequate processing practically detoxifies cassava leaves with considerable nutrient retention, thus enhancing utilization of cassava leaves for human consumption. PRACTICAL APPLICATIONS This study has clearly shown that cassava leaves are very nutritious. However, they also have anti-nutrients which can render them toxic. This is responsible for the fear exhibited in the consumption of cassava leaves because of anticipated poisoning. This study shows that African processing methods tremendously reduce the ant-nutrients with minimal loss in the nutrients. There should therefore be no fear in the utilization of cassava leaves either for animal feed formulation or man's own direct consumption as a good source of leafy vegetables. The food quality of processed cassava leaves renders them a potential source of raw material for the animal feed industry as well as for the formulation of weaning foods especially for the underdeveloped world.
Assessing Hand Hygiene Practices Among Nurses in the Kingdom of Saudi Arabia

300 nurses were approached to enroll 243 participants so the response rate was 81%. The study found that 65.4% (159) of the participants followed a good hand hygiene practice while 10.3% (25) showed inadequate hand hygiene practice. Good hand hygiene practice was found to be significantly higher among female participants (88%) than the male participants (44%). The participants from the department of internal medicine (43.5%) showed the highest percentage of inadequate hand hygiene practice while participants from the department of pediatrics reported a 100% good hand hygiene practice.
Investigations on the Thermal and Elastic Properties of ZnO-Incorporated Phosphate Glasses and Glass Ceramics

Abstract Glasses of the 45P2O5-(40-x)CaO-15Na2O-xZnO system with increasing zinc oxide (ZnO) concentrations within the ranges of 3 ≤ x ≤ 12 mol% were obtained by employing the melt-quench technique. ZnO inclusions in the phosphate glass network lead to increases in its density and, conversely, a decrease in its molar volume. On the basis of the obtained thermal analysis data, the glasses underwent thermal treatment, which helped to derive their glass ceramic equivalents. The evaluations of structural and elastic properties of glasses before and after thermal treatments were made using X-ray diffraction (XRD) studies and ultrasonic nondestructive testing. The differential thermal analysis data show the reduction in the crystallization tendency and increase in thermal properties, such as crystallization temperature (T P), thermal stability (T c – T g) (where Tc is crystallization onset temperature and T g is glass transition temperature), thermal stability parameter (S), and degree of glassification (D g) of phosphate glasses against the progressive additions of ZnO. The XRD of glass ceramics confirmed the dominance of metaphosphate, pyrophosphate, and ZnO-related crystalline features. The measured elastic moduli, such as longitudinal (L), shear (G), Young's (Y), and bulk (K), and Vicker's microhardness values increased in both glass and glass ceramics with an increase in ZnO incorporation. GRAPHICAL ABSTRACT