Miracle-dz/UniFAR-FTUs huggingface dataset:
Kinetics and Mechanisms of Unseeded Emulsion Polymerization of Methyl Methacrylate

ABSTRACTUnseeded emulsion polymerization of methyl methacrylate was carried out at 50 °C using sodium lauryl sulfate as emulsifier and potassium persulfate as initiator, respectively, to clarify the effects of emulsifier, initiator and monomer concentrations initially charged on the kinetic features of the polymerization such as the number of polymer particles produced and the course of polymerization. To describe the observed kinetic features, a quantitative kinetic model for particle nucleation and growth is proposed on the basis of the assumption that polymer particles are generated from emulsifier micelles. Furthermore, the rate coefficients for radical termination and propagation in the polymer particles are empirically correlated as a function of the weight fraction of polymer in the polymer particles. It is shown that by using these empirical rate coefficients and the proposed kinetic model, the observed monomer conversion versus time histories can be successfully simulated up to almost the end of .
Statistical Evaluation of Metal Concentrations as a Method for Identifying World Trade Center Dust in Buildings

The explosion and collapse of the World Trade Center (WTC) produced an aerosol plume of dust and smoke that impacted several buildings in lower Manhattan. Because of the potential health risks associated with the particulates generated from the WTC collapse, a method for identifying WTC dust is needed to prioritize the cleanup of impacted buildings. For this evaluation, a discriminant analysis model using known WTC and background indoor dust samples was developed to determine if metal concentrations could be used to differentiate between WTC dust and ordinary indoor dust. The sensitivity of the discriminant analysis model was evaluated by mathematically diluting the known WTC dust samples with indoor dust. This method is able to differentiate known WTC dust samples from indoor dust with an accuracy of 94%. In addition, this method can differentiate WTC dust with an accuracy of 80% up to a dilution of 2 parts WTC dust to 1 part indoor dust. The accuracy of the method does not fall below 50% until the WTC dust content of the dust falls below 56%. This illustrates the potential utility of using discriminant analysis with metals concentration data to identify WTC dust in indoor dust from buildings impacted by WTC dust.
RETENTION CAPACITY OF CHITOSAN FOR COPPER AND MERCURY IONS

Chitosan, was obtained from red lobster shells (Pleuroncodes monodon). The Mv of chitosan prepared was 54.000 g/mol with a deacetylation degree of 20%. The retention capacity of chitosan for copper and mercury ions was studied. The adsorption isotherms of Cu(II) and Hg(II) and the mixture of ions are discussed using the Langmuir and Freundlich model. The selectivity from the mixture of both ions was measured. The pH effect on retention was tested. Furthermore, the uptake of both ions in a mixture was compared using chitosan and a commercial resin Amberlite IRA-68
Comparative Analysis of Car Paint Traces in Terms of Color by VIS Microspectrometry for Forensic Needs

The usefulness of VIS microspectrometry for comparison of very small car paint traces was studied. Eighteen samples of solid and metallic paints taken from new and repainted cars were examined. Each sample was measured in both transmittance and reflectance mode (on top surface and on cross-section). Using the CIELAB units the repeatability of the color measurement was assessed. A criterion allowing two parts of the same sample and two samples of the same color to be distinguished was established. The method was proved to be an useful instrumental tool–complementary to other analytical methods (e.g., IR spectrometry)–in examination of car paint traces for forensic purposes.
Effect of organic manures and liquid organic manures on growth, yield and economics of aerobic rice cultivation.

Field experiment was conducted to know the response of organic manures on growth, yield, quality and economics of aerobic rice during Kharif 2011 at MARS, Dharwad. Results indicated that among organic treatments combined application of EC(1/3) + VC(1/3) + GLM(1/3) equivalent to RDF + FYM in combination with foliar application of jeevamrut @ 500 l ha ? 1 at planting, 30 and 60 DAS + panchagavya @ 5 per cent at panicle emergence and flowering stages recorded significantly higher growth parameters with higher grain yield (3837 kg ha ? 1 ) and straw yield (5855 kg ha ? 1 ) which was on par with control treatments i.e. , RDF + FYM and RDF only. But the net return (Rs.36,366) was higher with combined application of EC(1/3) + VC(1/3) + GLM(1/3) equivalent to RDF + FYM in a combination with foliar application of jeevamrut @ 500 l ha ? 1 at planting, 30 and 60 DAS + cow urine @ 10 per cent at panicle emergence and flowering stages and B:C (2.49) was higher with combined application of EC(1/3) + VC(1/3) + GLM(1/3) equivalent to RDN + cow urine @ 10 per cent at panicle emergence and flowering stages this might be due to lower cost of cultivation with these treatments.
Incidence of Boron Toxicity in Spring Barley in Southwestern Australia

Abstract One hundred and four crops of spring barley (Hordeum vulgare L. cv. Stirling) grown throughout southwestern Australia (WA) were surveyed for symptoms of boron (B) toxicity. Symptoms were identified as B toxicity and not spot-type net blotch, a foliar disease, caused by the fungus Pyrenohora teres f. spp. maculata that produces similar leaf symptoms. Symptoms of B toxicity occurred in 43 crops (about 40% of the surveyed crops) that were widely distributed in the <350 to 450 mm annual average rainfall zones of WA, on duplex soils with alkaline and fine-textured subsoils that were non-saline but sodic. Concentrations of mannitol-extractable B in sub-soils varied widely between 0.7 and 130 mg B/kg soil. Soil B concentrations measured in either mannitol or hot CaCl2 increased with soil depth and were highest where soil pH values were >8 (1:5 soil:0.01 M CaCl2, w/v). Concentrations of B in whole shoots (WS) were positively correlated with concentrations of hot CaCl2-extractable and mannitol-extractable soil B. The positive linear relationship between B concentration in WS and extractable-B in either mannitol or hot CaCl2 improved (R 2 value increased) with increasing soil depth, particularly in the 50 to 80 cm layer. Concentrations of B in the WS of barley plants with symptoms of B toxicity were found to vary between 4 and 76 mg B/kg dried WS. An additional study showed that symptoms of B toxicity developed in the later stages of Stirling barley growth [boot stage (GS 40) to maturity (GS 70)] grown on duplex soils with high concentrations of mannitol-extractable B in the sub-soils >30 cm from the soil surface. As toxic concentration of B occurred at late stages of Stirling barley development, reductions in grain yield resulting from B toxicity were small (up to 10%).
Drying of Fruits and Vegetables: Retention of Nutritional/Functional Quality

In the past, research and development in drying has focused on the process and technology and food drying was performed mainly to extended the shelf life without much importance on retaining quality attributes. Recently, however, efforts have been made to develop high-quality dried foods. This is achieved by utilizing novel drying technologies, by improving and optimizing existing drying methods, and by maximizing quality attributes such as structure, color, flavor, nutrition, etc. In an effort to highlight quality aspect of dried foods and biomaterials, a special issue of Drying Technology [2005, 23(4)] was published. The objective of this article is to present an overview of quality attributes normally considered in the drying of food and biomaterials and highlight the recent advances in drying methods for the retention of nutritional and functional properties of fruits and vegetables.
A comprehensive investigation of the mineral composition of brazilian bee pollen: geographic and seasonal variations and contribution to human diet

The mineral composition of bee pollen was investigated in 154 samples from different Brazilian regions. Ca, Cu, Fe, K, Mg, Mn, Na, P, Se and Zn were determined by ICP OES after microwave mineralization. Employing optimized instrumental parameters, the method was shown to have a good precision and accuracy for the simultaneous determination of minerals. Overall, samples from the Northeastern states presented significantly higher amounts of minerals and showed constant production throughout the year. Manganese, Se, Cu, Zn and Fe were the elements that showed the greatest possible contributions to the diet, contributing with 70, 37, 27, 17 and 17%, respectively, of the Brazilian recommended daily intake. Principal component analysis (PCA) was applied to study geographic effects. The elements Ca, Cu, Fe, K, Mg, Mn, Na, P and Zn were important in explaining the classification of pollen according to their geographical origin. The mineral levels varied widely during the year.
The Effect of Nanoparticle Hydrophobicity on the Rheology of Highly Concentrated Emulsions

Abstract A series of fumed silica nanoparticles were used as an additional emulsifier for highly concentrated (HC) waterin- oil (W/O) emulsions. These nanoparticles, with different hydrophobicity index (HI) in the 0.60- 1.34 and HI>3 range, were mixed with the conventional low molecular weight surfactant, sorbitan monooleate (SMO), in the oil phase prior to the emulsification process. The rheological properties of these emulsions were measured and compared with the properties of emulsions stabilized with SMO alone. In the mixed emulsifier system, the changes in rheological parameters were clearly expressed as a function of HI. The mixture of silica nanoparticles and SMO significantly increases the yield stress and plateau modulus of fresh emulsion, compared to the SMO only system. The effect was found to be more pronounced with a decrease in the HI. This is probably related to the reduction in micelle content with the decrease in HI, owing to a concomitant increase in the amount of SMO adsorbed onto the particle surface. Then, interestingly, the Foudazi-Masalova model recently developed for surfactant-stabilized highly concentrated emulsions (HCE) was found to describe successfully the rheological behavior of emulsions in the presence of a mixture of surfactant and fumed nanosilica.
Mechanisms leading to oligomers and SOA through aqueous photooxidation: insights from OH radical oxidation of acetic acid and methylglyoxal

Abstract. Previous experiments have demonstrated that the aqueous OH radical oxidation of methylglyoxal produces low volatility products including pyruvate, oxalate and oligomers. These products are found predominantly in the particle phase in the atmosphere, suggesting that methylglyoxal is a precursor of secondary organic aerosol (SOA). Acetic acid plays a central role in the aqueous oxidation of methylglyoxal and it is a ubiquitous product of gas phase photochemistry, making it a potential "aqueous" SOA precursor in its own right. However, the fate of acetic acid upon aqueous-phase oxidation is not well understood. In this research, acetic acid (20 μM–10 mM) was oxidized by OH radicals, and pyruvic acid and methylglyoxal experimental samples were analyzed using new analytical methods, in order to better understand the formation of SOA from acetic acid and methylglyoxal. Glyoxylic, glycolic, and oxalic acids formed from acetic acid and OH radicals. In contrast to the aqueous OH radical oxidation of methylglyoxal, the aqueous OH radical oxidation of acetic acid did not produce succinic acid and oligomers. This suggests that the methylgloxal-derived oligomers do not form through the acid catalyzed esterification pathway proposed previously. Using results from these experiments, radical mechanisms responsible for oligomer formation from methylglyoxal oxidation in clouds and wet aerosols are proposed. The importance of acetic acid/acetate as an SOA precursor is also discussed. We hypothesize that this and similar chemistry is central to the daytime formation of oligomers in wet aerosols.
A comparative study of three different types of barrier discharges in air at atmospheric pressure by cross-correlation spectroscopy

Microdischarges in a barrier discharge with an asymmetric electrode arrangement (‘metal–dielectric’) were investigated with fine temporal (down to 10 ps) and spatial (down to 10 µm) resolution by the technique of cross-correlation spectroscopy. The discharge was operated in dry air at atmospheric pressure. The spatio-temporal distributions of the light intensities of the 0–0 transitions of the second positive (λ = 337.1 nm) and first negative (λ = 391.5 nm) systems of molecular nitrogen were compared with the corresponding experimental results for a symmetric electrode arrangement (‘dielectric–dielectric’) and for the coplanar barrier discharge. For all the discharge types being considered, the mechanism of electrical breakdown was found to consist of the Townsend pre-breakdown phase, the phase of ionizing wave propagation and the decay phase. Despite the qualitative similarity of the microdischarge development in different electrode arrangements, a detailed comparison of certain discharge characteristics (ionizing wave velocity, spatially or temporally integrated light intensity) enables us to reveal the influence of the electrode configurations on the process of electrical breakdown.
Crystal structure of potassium trans-diaquabis[oxalato-κ2O,O] chromate(III) urea disolvate, K[Cr(C2O4)2(H2O)2]·2CO(NH2)2, C6H12CrKN4O12

Abstract C6H12CrKN4O12, triclinic, P1̅ (No. 2), a = 5.101(1) Å, b = 7.029(1) Å, c = 10.554(2) Å, α = 76.73(3)°, β = 77.46(3)°, γ = 81.32(3)°, V = 357.5 Å3, Z = 1, Rgt(F) = 0.0321, wRref(F2) = 0.1327, T = 293 K.
Optimization and characterization of remote plasma-enhanced chemical vapor deposition silicon nitride for the passivation of p-type crystalline silicon surfaces

In a recent letter [Lauinger et al., Appl. Phys. Lett. 68, 1232 (1996)] we have shown that record low effective surface recombination velocities Seff of 4 cm/s have been obtained at ISFH on low-resistivity (1 Ω cm) p-type crystalline silicon using microwave-excited remote plasma-enhanced chemical vapor deposition (RPECVD) of silicon nitride at low temperature (300–400 °C). As an important application, this technique allows a simple fabrication of rear-passivated high-efficiency silicon solar cells with monofacial or bifacial sensitivity. In this work, we present details of the required optimization of the PECVD parameters and a characterization of the resulting silicon nitride films. All deposition parameters are shown to strongly affect Seff as well as the stability of the films against the ultraviolet (UV) photons of terrestrial sunlight. A clear correlation between Seff and the film stoichiometry is observed, allowing a simple control and even a rough optimization of the surface passivation quality by .
Sorption behavior of hydroselenide (HSe−) onto iron-containing minerals

The sorption behavior of selenium onto iron-containing minerals such as goethite, ferrous oxide, magnetite, and biotite under reducing conditions were investigated by batch sorption experiments. Selenium was spiked as HSe− and Se42− in the experimental solutions and reducing conditions were maintained throughout the sorption periods. The sorption behaviors of HSe− were analyzed by the triple-layer surface complexation model with the Visual Minteq computer program. The sorption data and the model calculations suggested that the dominant sorption mechanisms of HSe− were inner-sphere surface complexation for goethite and ferrous oxide but outer-sphere surface complexation for magnetite and biotite. The intrinsic equilibrium constant of the inner-sphere surface complexation reaction of HSe− with goethite, logKintHSe = 6.0, was determined by the fitting to the experimental results. The value of the equilibrium constant for outer-sphere complexation for magnetite and biotite was estimated to be around 12.
Effect of arsenic on phytosiderophores and mineral nutrition of barley seedlings grown in iron-depleted medium

Abstract A hydroponic experiment with barley seedlings (Hordeum vulgare L. cv. Minorimugi) grown in iron (Fe)-depleted medium in the presence of added arsenic (As) at the rates of 0, 0.67, 6.7 and 67 µmol L−1 (equivalent to 0, 0.05, 0.5 and 5 mg L−1 As, respectively) showed that increasing the As concentration in the medium lowered the release of phytosiderophores (PS) and their concentration in the roots. This Fe-depleted experiment was conducted to clarify the effect of As on the release and concentration of PS in roots and on the phosphorus (P) and Fe concentrations in plants. The chlorophyll index increased substantially in the 67 µmol L−1 As treatment compared with the other treatments. This result indicated that higher concentrations of As might interrupt the appearance of Fe chlorosis in plants grown in Fe-depleted medium. Arsenic at a level of 67 µmol L−1 increased the Fe concentration and accumulation in shoots disappearing the whitish chlorosis. An increased concentration of Fe in the shoot might also be responsible for lowering the release and concentration of PS in the roots. Increases in the concentration of Fe in the shoot most likely resulted from enhanced Fe translocation from the roots to the shoots. The physiological mechanism of the higher Fe translocation with As needs to be investigated. Arsenic lowered the concentrations of P, potassium (K), calcium (Ca) and magnesium (Mg) in the shoot at the 67 µmol L−1 level. A higher Fe concentration and higher ratio of Fe/P in the shoot might be responsible for the greening of the leaves in the 67 µmol L−1 As treatment. The concentrations of manganese (Mn), zinc (Zn) and copper (Cu) were reduced by the high As levels. There was a concomitant increase in the As contents in shoots with higher As levels in the growth medium. The relationship between the concentrations of As and Fe and between P and Fe in the shoots was the opposite. Thus, higher As level might play a role in increasing the mobility of root Fe in barley tissues grown in Fe-depleted medium. Grasses grown under Fe-deficient conditions might not show Fe chlorosis in the presence of high concentrations of As.
Influence of size on the electrocatalytic activities of supported metal nanoparticles in fuel cells related reactions

Recent publications related to the investigation of the size dependence of the catalytic activities of supported metal nanoparticles in fuel cell-related processes, namely hydrogen oxidation, oxygen-reduction, CO, formic acid, formaldehyde, and methanol oxidation reaction, are reviewed. The experimental data as well as theoretical modeling are presented for the influence of the particle size on the structural, electronic, adsorption, and catalytic properties. Analyses of the available literature proves unambiguously that a decrease in the particle size below ca 5 nm strongly affects specific electrocatalytic activities in fuel cell-related processes, and this is of importance for the design of efficient catalysts for PEMFCs and DMFCs. Various approaches to explain the origin of the particle-size effects in electrocatalysis are analyzed, with the conclusion that the observed variations in the electrocatalytic activities are induced by the intrinsic particle-size effects, and are related to the changes in their structural and/or electronic properties, rather than by diffusion-related phenomena. Keywords: supported metal nanoparticles; particles size effect; interparticle distance; electrocatalysis; adsorption; CO oxidation; hydrogen oxidation; oxygen-reduction reaction; methanol oxidation
The challenge of primary gastric melanoma: a systematic review

Aim: Primary gastric melanoma is a rare clinical presentation. The purpose of this review was to compare the 1-year survival in patients who underwent surgery with patients who did not receive treatment. Patients & methods: A systematic search of databases for case reports and case series of primary gastric melanoma was conducted. Results: The mean survival of patients was 22 months. One-year survival was 56.5% with surgery, rising to 66% with adjuvant therapy. Mean survival of the surgical group was 21.05 months (±20.2) versus 4.5 months (±3.61) in the nonsurgical group. Conclusion: Primary gastric melanoma has a poor prognosis but early surgical intervention can have a significant impact on patient outcome. We reviewed the biology and clinical diagnosis of gastrointestinal melanoma and the current management options available.
Impacts of different management systems on the physical quality of an Amazonian Oxisol

The physical quality of Amazonian soils is relatively unexplored, due to the unique characteristics of these soils. The index of soil physical quality is a widely accepted measure of the structural quality of soils and has been used to specify the structural quality of some tropical soils, as for example of the Cerrado ecoregion of Brazil. The research objective was to evaluate the physical quality index of an Amazonian dystrophic Oxisol under different management systems. Soils under five managements were sampled in Paragominas, State of Para: 1) a 20-year-old second-growth forest (Forest); 2) Brachiaria sp pasture; 3) four years of no-tillage (NT4.); 4) eight years of no-tillage (NT8); and 5) two years of conventional tillage (CT2). The soil samples were evaluated for bulk density, macro and microporosity and for soil water retention. The physical quality index of the samples was calculated and the resulting value correlated with soil organic matter, bulk density and porosity. The surface layers of all systems were more compacted than those of the forest. The physical quality of the soil was best represented by the relations of the S index to bulk density and soil organic matter.
Artificial Intelligence in Gastrointestinal Endoscopy

Artificial intelligence (AI) is rapidly integrating into modern technology and clinical practice. Although in its nascency, AI has become a hot topic of investigation for applications in clinical practice. Multiple fields of medicine have embraced the possibility of a future with AI assisting in diagnosis and pathology applications. In the field of gastroenterology, AI has been studied as a tool to assist in risk stratification, diagnosis, and pathologic identification. Specifically, AI has become of great interest in endoscopy as a technology with substantial potential to revolutionize the practice of a modern gastroenterologist. From cancer screening to automated report generation, AI has touched upon all aspects of modern endoscopy. Here, we review landmark AI developments in endoscopy. Starting with broad definitions to develop understanding, we will summarize the current state of AI research and its potential applications. With innovation developing rapidly, this article touches upon the remarkable advances in AI-assisted endoscopy since its initial evaluation at the turn of the millennium, and the potential impact these AI models may have on the modern clinical practice. As with any discussion of new technology, its limitations must also be understood to apply clinical AI tools successfully.