Miracle-dz/UniFAR-FTUs huggingface dataset:
FTIR and XPS studies of surface chemistry of pyrite in flotation

Efficient separation of pyrite is of great importance for the metallurgical performance of flotation processes. Presently, separation of pyrite by flotation is becoming more and more important for reduction of sulfur in coal. In this work Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) were used to study the surface chemistry of pyrite in depression, activation and xanthate adsorption under conditions of controlled potential. Modifications of pyrite surfaces after treatment with depressants (lime, sulfur dioxide, sodium cyanide) and after activation with metal ions (Cu, Pb) were studied. The principal adsorption product identified on pyrite was dixanthogen whose formation started at about +0.15 V and +0.25 V (vs, SHE) in ethyl and amyl xanthate solutions, respectively. Copper xanthate was formed on copper(II) activated pyrite. Activation mechanism of pyrite by copper(II) salts is likely to be electrochemical where copper occurs as copper(I) on the surface of pyrite. Effective depression is achieved by sulfur dioxide and sodium cyanide. Depression at high pH is due to formation of iron(III) hydroxides. Calcium ions do not affect the electrochemistry but adsorb on pyrite and reduce the surface sites for dixanthogen adsorption.
Photoisomerization of an Azobenzene on the Bi(111) Surface

Modifying surface-bound molecular switches by adding side groups is an established concept for restoration of functionality which a molecule possesses in solution and which is often quenched upon adsorption. Instead of decoupling the photochromic unit from the substrate, we follow a different approach, namely treating the complete molecule–substrate system. We use photoelectron spectroscopies to determine the energetic positions of the frontier orbitals of di-m-cyanoazobenzene on Bi(111) and to elucidate the isomerization mechanism which is stimulated by a substrate-mediated electron transfer process.
Compressibility of microporous materials with CHA topology: 2. ALPO-34

Abstract The HP behavior of ALPO-34 as-synthesized was investigated by means of in-situ synchrotron X-ray powder diffraction, in the frame of a wider project aimed at understanding the role of the framework/extraframework content in the P-induced deformation mechanisms of natural and synthetic microporous materials with CHA framework topology. ALPO-34 compressibility under non-penetrating P-transmitting medium was determined up to 6.0 GPa and upon decompression to Pamb. After an initial large structure deformation at P < 0.4 GPa, a regular volume reduction was observed up to about 3 GPa. Above 3.1 GPa, an abrupt change in the behavior of all cell parameters was observed, accompanied by an evident decrease in compressibility. The isothermal Equation of State (EoS), refined with a II-order Birch–Murnaghan EoS from 0.4 to 3.1 GPa, yielded the following parameters: V0 = 755(1) Å3, K0 = 54(3) GPa. No complete X-ray amorphization was achieved up to the highest investigated P value. A complete reversibility of the unit cell parameters was observed upon P release. The compressibility behavior of ALPO-34 was compared with that of the other CHA-type zeolites. The volume reduction observed for natural chabazite, and for SAPO-34 and ALPO-34 as-synthesized, was 6.2%, 9.4%, and 6.0%, respectively. Notwithstanding the presence of morpholine molecules, as a structure directing agent, in the two as-synthesized phases, they exhibited significantly different compressibility. This can be interpreted as due to the octahedral coordination of part of the ALPO-34 framework aluminum, leading to a more rigid framework compared to that of SAPO-34, which contains only tetrahedral aluminum.
Study on cold storage effect of film packaging of spinaches

Spinaches(Spinacea oleracea)were packed in plastic skeps as control or packaged in plastic film bags without being sealed and stored at 9℃ for 33 days or at 2℃ for 45 days or 63 days to study the effects of film packaging without sealing and low temperature on storability of spinaches to select optimal storing method of the vegetable. Control spinaches lost water severely manifested by much higher weight-loss percent, as led to them wilting severely, and those stored at 9℃ yellowed severed. Pplastic packaging of spinaches without sealing and storing them at 2℃ could prevented them significantly form losing water, yellowing and rooting, therefore, maintained them fresh in appearance with storage period of more than 2 montns with yellowing percentage about 20%. When stored at 9℃, plastic film packing of spinaches also restrained them losing water effectively, but caused them rotted severely.
Co-gasification of Plastics and Biomass in a Dual Fluidized-Bed Steam Gasifier: Possible Interactions of Fuels

Co-gasification of biomass and plastics was investigated in a 100 kW dual fluidized-bed pilot plant using four types of plastic material of different origins and soft wood pellets. The proportion of plastics was varied within a broad range to assess the interaction of the materials. The product gas composition was considerably influenced by co-gasification, whereas the changes were nonlinear. More CO and CO2 were measured in the product gas from co-gasification than would be expected from linear interpolation of mono-gasification of the materials. Less CH4 and C2H4 were formed, and the tar content in the product gas was considerably lower than presumed. With the generation of more product gas than expected, co-gasification of wood and plastic materials also had other beneficial effects. Because of the fuel mixtures, more radicals of different types were available that interacted with each other and with the fluidization steam, enhancing the reforming reactions. Wood char had a positive effect on polymer d.
Pellet mass loading and pellet retention time for turbidity removal in a pelletisation process

A pilot scale pelletiser, after a special start-up with 3,000 mg/l kaolin, was tested continuously for 72-84 h for each run with water from a local river, the Chao Phraya, for its turbidity removal efficiency at different upflow velocities, i.e. (A) 9.6 and 15 m/h for the 'low' turbidity feed water of 30-60 NTU in the summer season, and (B) 6 and 9.6 m/h for the 'high' turbidity influent of 100-200 NTU in the rainy season. Alum, in doses of 3-10 mg/l for Case A and 19-26 mg/l for Case B, and 0.3 mg/l nonionic polymer, were used as the coagulant and coagulant aid for the two cases, respectively. Alternatively, the polymer, at doses of 0.1-0.3 mg/l, was used as the sole coagulant in the process. The aluminium to turbidity (Al/T) ratios were 0.004-0.015 and 0.014-0.022 g/g SS for Cases A and B, respectively. The polymer to turbidity ratio (P/T) was set at 0.0054-0.0059 and 0.0020-0.0030 g/g SS for the two cases, respectively. The pellet mass loading, in terms of the turbidity removal per pellet mass, was 0.40-0.76 and 0.13-0.21 (g SS/day)/g, or 0.90-1.21 and 0.13-0.20 raw water NTU/g, for the two cases respectively. The pellet retention time (PRT) or pellet age (thetac), required to produce water of better than 5 NTU quality, was 4.4-11.9 and 1.3-3.7 days for the two scenarios. The nonionic polymer was used as the destabilising coagulant with less satisfactory results. The PRT under this condition was, however, 4.8-11.9 and 2-3 days for Cases A and B, respectively. It is noted that the pellet size for both cases was similar, i.e. 0.18-0.22 mm diameter, with a corresponding high density of 1.06-1.12 g/cm3.
Influência da fertirrigação da nitrogenada na produtividade da cultuta da mamoneira

Among the oil used in the Brazilian Biodiesel Program (Pro-Biodiesel), the castor bean stands out due to high adaptability to adverse weather conditions and the multitude of industrial applications of its oil.The objective of the present work was to evaluate the effects of increasing doses of nitrogen, applied by fertigation, in the castor oil plant (Ricinus communis L.) cultivar IAC-Guarani. The experiment was implemented in an investigation site within the Federal University of Ceara, in the city of Fortaleza (03o44'S, 38o33'W, 19,5 m). The sowing of was made in holes with a depth from 3 to 5cm, in the spacing of 1,0 m x 1,0 m. The foundation manuring was composed of micronutrients (15 g of FTE BR-12) and phosphorus, in the form of MAP (1.740g). The macronutrients nitrogen and potassium were applied by fertigation on a weekly basis. During the cycle of the culture, the plants were irrigated daily using a drip irrigation system, where the water depths were quantified starting from 75% of the (ECA) evaporation measured in the class "A" pan. The experimental delineation was in blocks at random with five treatments: 0, 50, 100, 150, and 200% of the nitrogen recommended in the soil analysis, with four repetitions. The application of different doses of nitrogen through fertigation, influenced the following productive factors: weight of 100 seeds of the racemes of 2nd and 3rd orders, the productivity of the racemes of 3 rd order and total productivity of the plant. The estimated dose of nitrogen of 131% of the recommended by the soil analysis, was the one that provided the highest total productivity.
Field pilot evaluations of iron oxide‐based arsenic adsorption media

Field pilot tests were conducted with three hybrid adsorptive media to evaluate their performance at removing arsenic from groundwater. The media are based on polymeric resins loaded with iron oxyhydroxide nanoparticles and were evaluated with a commercially available granular ferric oxide media as a reference material at well sites in New Hampshire and Arizona. A full‐scale arsenic removal system in Connecticut is also discussed. The water chemistries of these three locations varied in terms of pH, arsenic concentration and speciation, and silica and phosphate content. Although all media were hybrid iron oxide materials, they exhibited different levels of performance and capacity under the specific pilot conditions because the effective operational life to remove arsenic is dependent on the chemistry of the treated water as well as the porosity of the base resin. The availability of the iron phase for arsenic binding is an important parameter, particularly in dynamic column applications.
När skolan själv får välja : en ESO-rapport om friskolornas etableringsmönster

I rapporten analyseras vilka faktorer som paverkar var friskolor valjer att etablera sig.Rapporten konstaterar att friskolor oftare etableras i omraden med manga hogutbildade – men ocksa i invandra .
A Work Project, presented as part of the requirements for the Award of a Master Degree in Finance from the NOVA-School of Business and Economics. THE EFFECTS OF THE ECB’S UNCONVENTIONAL MONETARY POLICIES ON STOCK MARKETS

The purpose of this research is to analyse the impact of the ECB’s unconventional monetary policies on European Stock Markets since the beginning of the financial crisis. In order to do so, I conduct an event study founded on the application of three different models, which are robust to the heteroscedasticity and autocorrelation of daily stock returns. My results suggest that the ECB’s unconventional monetary policy announcements had significant and positive effects on Italian, Spanish and Portuguese equities. Contrarily, the impact is negative for German stocks. Regarding the industries, the highest positive impact was on the banking sector.
Acute Decrease in Left Ventricular Diastolic Chamber Distensibility During Simulated Angina in Isolated Hearts

It is not clear what factors contribute to the prompt and reversible decrease in left ventricular diastolic chamber distensibility during angina pectoris that is induced by an increase in myocardial energy demand due to exercise or pacing tachycardia. To simulate the demand ischemia that occurs clinically during pacing-induced angina, we used isolated, blood-perfused rabbit hearts with restricted coronary flow and increased myocardial energy demand. A constant left ventricular balloon volume model was used to measure left ventricular diastolic chamber distensibility during 6 minutes of low-flow global ischemia, induced by a reduction in coronary perfusion pressure from 100 to 20 mm Hg. To investigate the influence of different levels of myocardial energy demand, the effects of two different heart rates were studied during low-flow global ischemia; pacing tachycardia (6.4 ± 0.2 Hz, n = 7) was compared with the rabbit's baseline heart rate of 4 Hz (n = 7). Low-flow ischemia caused a marked decrease in contractile function relative to the baseline preischemic state. In the pacing-tachycardia group, myocardial energy demand, as estimated by the rate ± systolic pressure product, was significantly greater than in the constant heart-rate group. When tachycardia was imposed during low-flow global ischemia, there was a transient and reversible increase in isovolumic left ventricular end-diastolic pressure from 14 ± 1 to 25 ± 4 mm Hg (measured during long diastoles obtained with transient cessation of pacing) in the pacing-tachycardia group, but there was no increase in left ventricular end-diastolic pressure during low flow ischemia in the constant heart-rate group with lower energy demand (p<0.01). The time constant of left ventricular relaxation also markedly increased in low-flow ischemia combined with pacing tachycardia. Glycolytic flux (as estimated by coronary venous-arterial lactate concentration difference) increased during low-flow ischemia at the baseline heart rate of 4 Hz but did not increase further during the elevated energy demand of pacing tachycardia. We conclude that in isolated, blood-perfused hearts, global myocardial ischemia due to a reduction in coronary flow alone is not associated with a decrease in diastolic chamber distensibility. However, when a pacing-induced increase in myocardial energy demand is superimposed on the ischemic myocardium and exceeds its capacity to generate high-energy phosphates, a rapid and reversible decrease in left ventricular diastolic chamber distensibility develops similar to that which occurs in response to pacing-induced angina in humans. This finding in isolated, blood-perfused hearts with global ischemia supports the hypothesis that the increase in left ventricular diastolic pressure that occurs during angina in humans is related to the effects of demand ischemia on myocardial relaxation per se and does not require dyssynchronous contraction of ischemic and nonischemic segments, nor does it depend on pericardial or right ventricular factors.
Extraction complexes of Pu(IV) with carbamoylmethylphosphine oxide ligands: A relativistic density functional study

Abstract The extraction complexes of Pu(IV) with n-octyl(phenyl)-N,N-diisobutyl-methylcarbamoyl phosphine oxide (CMPO) and diphenyl-N,N-diisobutyl carbamoyl phosphine oxide (Ph2CMPO) have been studied by using density functional theory (DFT) combined with relativistic small-core pseudopotentials. For most complexes, the CMPO and Ph2CMPO molecules are coordinated as bidentate chelating ligands through the carbonyl oxygen and phosphoric oxygen atoms. The metal-ligand bonding is mainly ionic for all of these complexes. The neutral PuL(NO3)4 and PuL2(NO3)4 complexes are predicted to be the most thermodynamically stable molecules according to the metal-ligand complexation reactions. In addition, hydration energies may also play a significant role in the extractability of CMPO and Ph2CMPO for the plutonium cations. In most cases, the complexes with CMPO possess qualitatively similar geometries and electron structures to those with Ph2CMPO, and they also have comparable metal-ligand binding energies. Thus, replacement of alkyl groups by phenyl groups at the phosphorus atom of CMPO seems to have no obvious influence on the extraction of Pu(IV).
Depression in Type 2 Diabetes Mellitus Patients Attending a Tertiary Care Hospital in North Karnataka: A Hospital-Based Descriptive Study

Introduction : Diabetics have a higher risk of having depression when compared to normal population. India has the one of the largest diabetic populations many of the treating physicians fail to recognize the underlying depression of patients with diabetes mellitus . The objective of the study was to find out the prevalence of depression in patients with established Type II diabetes mellitus patients. Materials and Methods : The present study is a hospital-based cross-sectional descriptive study. The study was undertaken in patients attending outpatient department of tertiary care hospital. A total of 150 patients with established T2DM were evaluated for depression by administering the 21-item Beck Depression Inventory (BDI) scale. Results : In the present study, 54.4% of the participants were found to be having depression, which ranged from mild to severe, most of the them had only mild symptoms. Most of the study participants, that is, about 22% belonged to the age group of 51–60 years followed by 18% in 41–50 years. In the present study, depression was found more in females (30.66%) than in males (24.66%). In this study, majority of the patients (33.3%) on OHA were not depressed, whereas 15.2% of patients on insulin and OHAs were depressed. A total of 48% of the patients with comorbidities were depressed in the present study. Conclusion : The diabetic patients are more prone to have depression, therefore, it is necessary for the well-being of diabetic patients that the patients are assessed for the presence or development of depression. Key words: Becks Depression Inventory, depression, diabetes
Mixed-ligand coordination of the (UO2)2+ cation and apophyllite topology of uranyl chlorochromate layer in the structure of ((CH3)2CHNH3)[(UO2)(CrO4)Cl(H2O)]

Abstract Addition of the Cl-0 anions to the synthesis mixture stabilizes specific structures of uranyl complexes which results in new compounds with the unprecedented structural topologies. ((CH3)2CHNH3)[(UO2)(CrO4) · Cl(H2O)] is a new member of the small family of compounds based upon the Ur(XmOn)5 (X = Cl, Br, I) bipyramids. The structure is based upon uranyl chloride chromate layers that alternate with the layers of protonated amine molecules. The layers contain UrClO4 pentagonal bipyramids that share three of its equatorial corners with CrO4 tetrahedra. Topological analysis shows that the [(UO2)(CrO4)Cl(H2O)]-0 layer belongs to the same topology of interpolyhedral linkage as in α-UO2MoO4(H2O)2. This type of topology (linkage of 4-membered rings creating 8-membered rings) is known in silicate crystal chemistry as the topology of the [Si4O10] layers in the minerals of the apophyllite group. Their linkage via various intermediate units results in a large family of open-framework and pillared silicates.
Influence of electrolyte on cadmium interaction with selected andisols and alfisols

The adsorption-desorption ofcadmium (Cd) as a function ofpH, ionic strength, and composition of the electrolyte was examined for four variable charge soils: two Alfisols from Zimbabwe (Mazowe and Bulawayo) and two Andisols from Spain (Realejos-1 and Realejos-2). At the natural soil pH, Cd adsorption measured in 0.01 mol dm -3 NaNO 3 was related to the net negative surface charge ofthe soils. Most of the Cd adsorbed in the four soils was strongly bonded. Increasing pH increased the surface negative charge of all soils. Adsorption of Cd also increased continuously with rising pH, and part of the variation in adsorption with pH was explained by the variation in the negative surface charge. Desorption decreased as the pH increased and became a trace at pH > 6. Differences in extractability between the two groups of soils were considered to be related to differences in the characteristics of the soil matrix. Increasing the concentration of the electrolyte from 0.001 to 0.1 mol dm -3 NaNO 3 caused a decrease in Cd adsorption and enhanced the amount of sorbed metal that could subsequently be desorbed. Variations in the initial pH ofthe soil suspensions, however, accounted for part ofthe effect. This pH-ionic strength interaction was even more evident when the most dilute electrolyte was used. Adsorption was reduced in the Ca-electrolyte compared with the Na-electrolyte. Calcium, on the contrary, increased Cd desorption.
X-ray crystal structures of specifically substituted and derived 4,4′-dihydroxybiphenyls. Influence of the structural modification

Abstract A systematic series of compounds featuring bromo and nitro substituted derivatives or dimethoxy analogs of 4,4′-dihydroxybiphenyl are comparatively studied with reference to their crystal structures showing specific influence of the structural modification both on molecular conformation and packing of the molecules. While bromine substitution of the parent biphenol does not fundamentally affect the typical O-H.O generated layer structure, nitro substitution prevents corresponding layer formation due to intramolecular hydrogen bonding. On the other hand, in the case of the less strongly bound dimethoxy analogue, bromine substitution is strong enough to obstruct the C-H.O involved layer architecture, demonstrating a graded effect of substituents on the crystal structures of biphenol type compounds.
Validation of a new method for spectrophotometric determination of polyethylenimine

ABSTRACT A new method of determination of polyethylenimine (PEI) is presented. The method is fast, reliable, and easy to perform. It is based on a creation of a complex between Cu2+ and PEI and its absorption in UV–VIS spectrum. The complex has a distinct absorption peak in UV part of electromagnetic spectrum and the measurement is optimal at 285 nm. A method is thoroughly analyzed in various concentrations of both PEI and Cu2+, temperatures, times of creation of a complex, ionic strengths, background electrolytes types, and pH values. Analytical parameters of the presented method such as linearity, sensitivity, limit of detection (LOD), limit of quantification (LOQ), repeatability, and intermediate precision were also determined.
Fast gelation of self-assembling peptide nanofibres triggered by electromagnetic radiation heating

Peptides and peptide amphiphiles are able to form nanoscale ordered hydrogels. We report a method for the preparation of such nanofibre based gels. These gels are prepared by a rapid microwave heating and cooling cycle. An amphiphilic derivative of the hydrophilic hexapeptide dalargin, in which a C16 acyl chain is attached via an ester linkage to the tyrosine residue (palmitoyl dalargin – pDal) was used to construct the nanofibre gels. The thermal properties of pDal were analyzed using differential scanning calorimetry (DSC) and Hot Stage Microscopy (HSM). When a dilute dispersion of pDal freeze dried solid (1mg mL) is microwave heated in short bursts, at the acyl chain melting temperature (88°C, 10) nanofibres with a diameter of 8-20 nm are formed; heating a more concentrated dispersion (10 mg mL) results in the formation of a nanofibre gel. Our findings show that microwave heating of peptide amphiphiles, bearing acyl chains is a reproducible method of producing peptide nanofibre gels.
Bromide's effect on DBP formation, speciation, and control: part 1, ozonation

The effect of variable ozone dosage and bromide concentration on the formation of organic disinfection by-products (DBPs) and bromate were evaluated. Low ozone dosages resulted in oxidation of organic precursors, yielding decreases in the formation potential for total trihalomethanes (THMs), six haloacetic acids (HAAs), and total organic halide (TOX). Increasing the ozone dosage oxidized bromide to bromate, decreasing the bromide for incorporation into DBPs. Bromate concentrations were linearly correlated with ozone residuals. Changes in the bromine incorporation factors n and n[prime] reflected differences in the resulting speciation of THMs and HAAs, respectively. Because TOX measurements based on chloride equivalence may underestimate the halogenated DBP yield for high-bromide waters, a procedure is described whereby bromide and bromate concentrations were used to correct the TOX measurement.