Miracle-dz/UniFAR-FTUs huggingface dataset:
Mathematical Modeling of Batch Emulsion Copolymerization Processes

A general mathematical model for emulsion copolymerization processes in batch reactor is presented. The model predicts the time‐history of monomer conversion, average particle size, copolymer composition and number of particles. The model was tested and validated with experimental data of four different copolymerization systems: S/MMA (styrene/methyl methacrylate), S/BA (styrene/butyl acrylate), MMA/BA (methyl methacrylate/butyl acrylate) and MMA/VA (methyl methacrylate/vinyl acetate). The influence of several process variables, such as initiator concentration, emulsifier concentration, monomer‐to‐water ratio, and composition has been examined. Model predictions presented satisfactory agreement with the experimental data. Despite the model simplicity and the reduced number of adjustable parameters, the model accounts for the basic features of emulsion polymerization processes and can be useful for practical applications.
Wet oxidation of GeSi strained layers by rapid thermal processing

A cold‐wall rapid thermal processor is used for the wet oxidation of the commensurately grown GexSi1−x layers on Si substrates. The rate of oxidation of the GexSi1−x layer is found to be significantly higher than that of pure Si, and the oxidation rate increases with the increase in the Ge content in GexSi1−x layer. The oxidation rate of GexSi1−x appears to decrease with increasing oxidation time for the time‐temperature cycles considered here. Employing high‐frequency and quasi‐static capacitance‐voltage measurements, it is found that a fixed negative oxide charge density in the range of 1011– 1012/cm2 and the interface trap level density (in the mid‐gap region) of about 1012/cm2 eV are present. Further, the density of this fixed interface charge at the SiO2/GeSi interface is found to increase with the Ge concentration in the commensurately grown GeSi layers.
Optimum pyrochlore compositions for low thermal conductivity

The thermal conductivities of 40 pyrochlores with the composition A2B2O7 (A = La, Pr, Nd, Sm, Eu, Gd, Y, Er or Lu; B = Ti, Mo, Sn, Zr or Pb) are predicted by molecular dynamics simulations. The trends in the behaviour can be fully understood in terms of the differences in the density and the speed of sound in the materials. Increased structural disorder, arising from O diffusion in most of the Pb-containing systems, leads to a further reduction in the thermal conductivity. We suggest strategies for lowering the thermal conductivity even further.
Constructing a Graphic Organizer in the Classroom: Introductory Students' Perception of Achievement Using a Decision Map To Solve Aqueous Acid Base Equilibria Problems.

Common examples of graphic organizers include flow diagrams, concept maps, and decision trees. The author has created a novel type of graphic organizer called a decision map. A decision map is a directional heuristic that helps learners solve problems within a generic framework. It incorporates questions that the user must answer and contains conceptual as well as methodological knowledge. The decision map that is presented was created to solve pH problems of varying difficulty that introductory college chemistry students encounter when studying acid–base equilibria. The acid–base decision map was created during an in-class workshop with approximately sixty students enrolled in the second semester of a two-semester introductory chemistry course for science and premedical majors. Questionnaires were used to measure studentsâ€™ perceptions of achievement in regard to problem solving, understanding of concepts, and organization of information as it related to the decision map. Open-ended comments were also s.
Caractérisation et modélisation du séchage de trois produits tropicaux : manioc, gingembre et gombo

Une etude experimentale du sechage par convection forcee, en couche mince (0,5 a 3 cm d'epaisseur) a ete realisee sur trois produits agricoles (le manioc, le gingembre et le gombo) a l'aide d'une soufflerie a conditions aerauliques et thermiques controlees. Cette etude a permis d'apprecier le comportement thermodynamique des produits pour differentes conditions de sechage (temperature de l'air de sechage 40 et 55 °C, vitesses d'ecoulement 0,5 a 3 m.s -1 , humidite absolue d'environ 15 g eau /kg air sec ) et d'identifier les meilleures valeurs des parametres caracteristiques du sechage par la methode de la Courbe Caracteristique Sechage (CCS). Il a ete etabli des correlations semi-empiriques qui permettent d'approcher au mieux les courbes experimentales obtenues lors des essais de sechage et de l'etude des isothermes de desorption obtenues par la methode gravimetrique a controle discontinu du poids de l'echantillon.
Pengaruh Model Pembelajaran Inkuiri dengan Teknik Scaffolding Terhadap Kemampuan Literasi Sains dan Prestasi Belajar IPA

Penelitian ini bertujuan untuk mengetahui pengaruh model inkuiri dengan teknik scaffolding terhadap kemampuan literasi sains dan prestasi belajar IPA. Rancangan penelitian ini menggunakan pola dasar Single Facorial Independent Group Design dengan jenis eksperimen semu. Sampel penelitian berjumlah 58 siswa. Data yang dikumpulkan adalah kemampuan literasi sains dan prestasi belajar IPA. Data dianalisis dengan menggunakan MANOVA berbantuan SPSS 17.00 for windows. Hasil Penelitian menunjukkan bahwa: Pertama, kemampuan literasi sains siswa yang mengikuti pembelajaran dengan model inkuiri teknik scaffolding secara signifikan lebih baik daripada siswa yang mengikuti pembelajaran dengan model konvensional (F = 19,982; p < 0,05). Kedua, prestasi belajar IPA siswa yang mengikuti pembelajaran dengan model inkuiri teknik scaffolding secara signifikan lebih baik daripada siswa yang mengikuti pembelajaran dengan model konvensional (F = 13,268; p < 0,05). Ketiga, secara simultan kemampuan literasi sains dan prestasi belajar IPA antara siswa yang mengikuti pembelajaran dengan model inkuiri teknik scaffolding secara signifikan lebih baik daripada siswa yang mengikuti model pembelajaran konvensional. Kata kunci: model inkuiri, teknik scaffolding, kemampuan literasi sains, prestasi belajar IPA
Appearance of half-metallicity in the quaternary Heusler alloys

I report systematic first-principles calculations of the quaternary Heusler alloys, e.g. Co2[Cr1−xMnx]Al, Co2Mn[Al1−xSnx] and [Fe1−xCox]2MnAl. I show that these alloys are also half-ferromagnets when the normal Heusler compounds corresponding to concentration values of zero and unity are half-metals. Moreover, the total spin moment Mt in μB scales linearly with the total number of valence electrons Zt (and thus with the concentration x) following the relation Mt = Zt−24, independently of the origin of the extra valence electrons, confirming the Slater–Pauling behaviour of the normal Heusler alloys. These results pave the way for experimentalists searching for new half-metallic alloys.
Investigation into the pressure-dependence between 1 and 10 Torr of the reactions of NO2 with CH3 and CH3O.

The kinetics and pressure dependence of the reactions of NO2 with CH3 and CH3O have been investigated in the gas phase at 298 K, at pressures from 1 to 10 Torr. A low-pressure discharge-flow laser-induced fluorescence (LIF) technique was used. In a consecutive process, CH3 reacted with NO2 to form CH3O, CH3+ NO2→ CH3O + NO (1), which further reacted with NO2 to form products, CH3O + NO2→ products (2). Reaction (1) displayed no discernible pressure dependence over the pressure range 1–7 Torr, and k1 was calculated to be (2.3 ± 0.3)× 10–11 cm3 molecule–1 s–1. Reaction (2) displayed a strong pressure dependence and an RRKM analysis yielded the following limiting low- and high-pressure rate constants in He, k0= 5.9 × 10–29 cm6 molecule–2 s–1 and k∞= 2.1 × 10–11 cm3 molecule–1 s–1. It is unrealistic to quote errors for this type of analysis. Parametrisation in the standard Troe form with Fc= 0.6 yielded k0=(5.3 ± 0.2)× 10–29 cm6 molecule–2 s–1 and k∞=(1.4 ± 0.1)× 10–11 cm3 molecule–1 s–1. Atmospheric implications and possible reaction mechanisms are discussed.
Liquid Radial Dispersion in Liquid-solid Circulating Fluidized Beds with Viscous Liquid Medium

Abstract Liquid dispersion in the radial direction was investigated in the riser of a viscous liquid-solid fluidized bed 0.102 m in diameter and 3.5 m in height. Pressure fluctuations in the riser were also measured and analyzed to examine the behavior of fluidized particles. Effects of liquid velocity (0.15–0.45 m/s), solid circulation rate (2–8 kg/m2s), particle size (1–3 mm), and liquid viscosity (0.96–38 mPas) on pressure fluctuations and the liquid radial dispersion coefficient were determined. The infinite space model was employed to obtain the radial dispersion coefficient from the radial concentration profiles of the tracer. The pressure fluctuations were analyzed by means of autocorrelation coefficient as well as power spectral density function. The dominant frequency obtained from the autocorrelation coefficient or power spectral density function of pressure fluctuations decreases with increasing liquid viscosity or liquid velocity, but it increases with increasing particle size. The liquid radial dispersion coefficient decreases with increasing liquid velocity or viscosity, but it increases as the solid circulation rate or particle size increases. The liquid radial dispersion coefficient is related closely to the resultant behavior of fluidized particles. The radial dispersion coefficient has been well correlated with operating variables in terms of dimensionless groups.
Evaluating LFWD Testing for Characterizing Subgrade Layers Using Regression Analysis and Artificial Neural Network Model

The Light Falling Weight Deflectometer (LFWD) was developed to estimate the in-situ elastic modulus directly to the layers near the base as subgrade and subbase layers. The field tests were carried out on selected sections from landfill project within Anbar Province. Furthermore, Forty test sections have been constructed and tested at the Civil Engineering Department- University of Anbar. All sections were tested using the ZFG 3000 model - LFWD in companion with the Plate Load Test (PLT) which were used as reference measures. Regression analyzes were performed to determine the best correlation between the elastic modulus obtained from LFWD and PLT tests. ANN model was used to calculate E vd and compare the regression statistical model. It was found that the ANN model showed a higher performance than regression analysis in predicting E vd . Satisfactory correlations were obtained, which showed that LFWD could be a promising device for in-situ characterizing of subsurface and subgrade layers.
Cation self‐diffusion in single‐crystal MgO

Cation self‐diffusion coefficients have been obtained for MgO in an argon atomosphere over a temperature range 1000–2400°C from concentration gradients determined with the aid of mass spectrometry. The problems associated with use of the short‐lived radioisotope 28Mg were avoided by employing the stable isotope 26Mg as a tracer. Samples were prepared utilizing vapor‐exchange, thick‐film, and semi‐infinite source boundary conditions at high, intermediate, and low temperatures, respectively, and were protected from contamination and volatilization by encapsulation in cylinders of pressed MgO powder. No significant difference in transport behavior was noted between crystals of moderate quality and those of the highest purity presently available. The temperature dependence of the diffusion coefficients may be represented by an activation energy of 2.76±0.08 eV and D0 of 4.19 × 10−4 cm2/sec. These parameters are comparable to those previously reported for impurity ion diffusion. The activation energy obtained .
Metabolic engineering of cyanobacteria for ethanol production

Development of renewable energy is rapidly being embraced by our society and industry to achieve the nation's economic growth goals and to help address the world's energy and global warming crises. Currently most of the bioethanol production is from the fermentation of agricultural crops and residues. There is much debate concerning the cost effectiveness and energy efficiency of such biomass based ethanol production processes. Here, we report the creation of a Synechocystis sp. PCC 6803 strain that can photoautotrophically convert CO2 to bioethanol. Transformation was performed using a double homologous recombination system to integrate the pyruvate decarboxylase (pdc) and alcohol dehydrogenase II (adh) genes from obligately ethanol producing Zymomonas mobilis into the Synechocystis PCC 6803 chromosome under the control of the strong, light driven psbAII promoter. PCR based assay and ethanol production assay were used to screen for stable transformants. A computerized photobioreactor system was established for the experimental design and data acquisition for the analysis of the cyanobacterial cell cultures and ethanol production. The system described here shows an average yield of 5.2 mmol OD730 unit−1 litre−1 day−1 with no required antibiotic/selective agent.
SIMULATION OF THE EFFECT OF AIR VELOCITY IN THE DRYING OF HARDWOOD TIMBER

ABSTRACT The effects of different air velocities on the drying of Australian hardwood timber have been investigated using a drying model based on Fickian diffusion. The air velocities studied were 0.05, 0.5, and 2 m.s-1, corresponding to typical velocities covering the range used from pre-drying to normal kiln conditions. Decreasing tbe air velocity from 2 m.s-1 to 0.05 m.s-1 reduces the maximum strain experienced with an optimised drying schedule by 34%, although if the lower velocity is used throughout the drying period, the drying time is predicted to be 40% longer. Explorations with a program to optimise drying schedules suggest that there may Dot be any significant advantage in moving from a low air velocity of 0.05 m.s-1 to a higher one (2 m.s-1) in terms of reducing drying time, for the same maximum strain during drying, compared with using a constant air velocity of 0.5 m.s-1.
Relationships Between Selected Properties of Starches from Different Corn Lines

Starch was isolated from the corn lines obtained by crossing two different germ pools (MS and Tux pool) and evaluated for amylose content, swelling power, solubility, water binding capacity (WBC) and syneresis. The gelatinization (To, Tp, Tc, ΔHgel, PHI & R) and pasting (pasting temperature, peak viscosity, breakdown viscosity, final viscosity and set back) properties of starches were measured using Differential Scanning Calorimeter (DSC) and Rapid Visco Analyzer (RVA), respectively. The relationships between different properties were also determined using pearson correlation coefficients. Amylose content was negatively correlated to swelling power and WBC (p < 0.05). Several significant relationships were also observed between thermal and pasting properties of isolated starches. Transition temperatures (To, Tp & Tc) and PHI showed positive correlation with peak, trough and breakdown viscosity (p < 0.05). Syneresis of starches was positively correlated to amylose content (p < 0.05).
Postfunctionalization of Luminescent Bipyridine PtII Bisacetylides by Click Chemistry

The synthesis of a family of differently substituted 5- and 4,4′-ethynyl-bpy PtII bisacetylide complexes (bpy = 2,2′-bipyridine) and their postfunctionalization using click chemistry is described. CuI-catalyzed azide–alkyne [3+2] cycloaddition was an efficient method to decorate the PtII complexes with a manifold of moieties in high yields. The absorption and emission properties and the electrochemical behaviour of all of the complexes have been investigated. The studied compounds emit at room temperature between 598 and 660 nm, reaching photoluminescence quantum yields of 0.33 in solution. The bright luminescent properties of the unsubstituted bpy PtII bisacetylide complex remained unaffected upon click-functionalization as the resulting triazole substituent has no significant influence on the nonradiative decay rate constant. This route opens new possibilities for to control the bulk of the complexes, their solubility, and their further extension or immobilization on macromolecules, polymers and surfaces without affecting their intrinsic properties. Two derivatives were selected as triplet emitter molecules in solution-processed polymer-based organic light-emitting devices.
Atrazine interactions with clay minerals : kinetics and equilibria of sorption

A novel technique using on-line microfiltration and HPLC analysis has been rued to study sorption kinetics and sorption equilibrium of the herbicide atrazine with the clay minerals montmorillonite, kaolinite, and illite and the clay fraction of a soil. Fast and slow labile sorption have been observed for atrazine along with a reversible but kinetically slow sorption/desorption process that is consistent with diffusion of pesticide into the interior of the clay particles. Labile sorption capacity, mole fraction site coverage, labile sorption equilibrium function, and distribution coefficient were determined for the clay minerals un aqueous slurries with atrazine
Is Primary Cesarean Section a Cause of Increasing Cesarean Section Rates in Greece?

Introduction: Cesarean Section is a surgical procedure which can be life saving and necessary in some circumstances. Nonetheless, Cesarean Delivery continues to result in increased complications for subsequent deliveries as well as increased financial costs. This phenomenon raises concerns over the growing rates of Cesarean deliveries among women at low risk for a complicated birth whose first delivery was by Cesarean Section for non-medical reasons. Aim: The aim of this study was to determine whether PCS is a main factor in the overall percentage of CS in Greece and define the causes of elective and emergency cesarean sections in primary ones. Methods: From 365 cesarean deliveries during the research period, a sample of 162 women who underwent a primary cesarean section at a Greek University hospital has consented to participate. Medical and demographic data as well as data from women’s medical dossier were used in the day 3 postpartum. Results: Out of 162 primiparous mothers, 38.9% underwent an emergency cesarean section and 61.1% an elective cesarean section. Furthermore, the results show that women, who had been diagnosed with stress disorders or depression, with abnormal fetal heart rate, pathological NST/Doppler and had developed complications after cesarean section, were more likely to undergo an emergency cesarean delivery. Conclusion: This survey shows the lack of evidence-based guidelines in obstetrician’s practice and the lack of perinatal support centers in Greece. Primary CS can be characterized as a key factor in the overall increase of CS, given the vicious cycle of recurrence of a Cesarean delivery.
On the electrical properties of some modified polysulfones in thin films

Abstract The temperature dependence of the electrical conductivity and the Seebeck coefficient for some chelate-modified polysulfones (PSF-Cs) derived from chloro-terminated polysulfones and bis (2,4-dihydroxybenzaldehyde) Cu2+ were studied. The measurements were performed using the thin films deposited from solution. The investigated polymers have semiconducting properties. The correlations between these properties and the molecular structure of the respective polymers are discussed.
Solvent Extraction of Iron(III) from Chloride Media by N-Methyl-N-alkyloctanamide Derivatives

Abstract N-methyl-N-cyclohexyloctanamide (MCHOA) and N-methyl-N-phenyloctanamide (MPHOA) were synthesized, characterized, and tested to recover iron(III) from chloride media. Both compounds efficiently extract Fe(III) from HCl solutions above 4 M, although a decrease in extraction at 10 M HCl, involving MCHOA, is noticed. Stripping of Fe(III) by water may be easily and efficiently achieved. Results on the re-utilization of the organic phases are also presented. Preliminary selectivity experiments point out to a rather good performance of both compounds towards Fe(III) when in the presence of Cu(II), Ni(II), and Zn(II). Assuming that the extractants are under a monomeric form, average species such as (L, MCHOA or MPHOA) are proposed as being involved on Fe(III) extraction from 6 M HCl solutions.
Comparative Evaluation of Combustion, Performance, and Emissions of Jatropha Methyl Ester and Karanj Methyl Ester in a Direct Injection Diesel Engine

Biodiesel prepared from different vegetable oils and fats are likely to have some comparative advantages and disadvantages. Two major oil varieties, considered suitable for biodiesel making are Jatropha curcas and Pongamia pinnata. This study targets at making a comparison of the methyl esters of these oils in a diesel engine against diesel fuel. The performances of the fuels was evaluated in terms of thermal efficiency, specific fuel consumption, power output and mean effective pressure, cylinder pressure, rate of pressure rise, and heat release rates. The emissions of carbon monoxide (CO), carbon dioxide (CO2), unburnt hydrocarbon (HC), oxides of nitrogen (NOx), and smoke opacity with the three fuels were also compared. Both varieties of the oil, after transesterification, exhibit the major properties within acceptable limits of biodiesel standards set by many countries. Karanj methyl ester (KME) performed better than jatropha methyl ester (JME), whereas the shortest ignition delay is observed with JME.
Biological agents and work-related diseases: results of a literature review, expert survey and analysis of monitoring systems: litertature review

This report forms part of a major project to address the risks posed by biological agents in the workplace. The aim of the project is to raise awareness of exposures to these hazards at work, provide more information on the related health problems and support efforts to prevent them. The report presents the results of a scientific literature review, a survey of experts and an analysis of selected systems used by European Union Member States for monitoring diseases and exposures. It assesses the existing knowledge on the subject, including on new and emerging risks, identifies gaps in the data, and makes recommendations to improve the monitoring and prevention of these widespread but poorly understood risks. Including executive summary.
Does economic growth and financial development spur energy consumption in Tunisia

This study investigates the link between energy consumption, financial development and growth in Tunisia. The causal relationship between energy consumption growth (ENC), per capita GDP growth (GDP) and credit to the private sector as a proxy of financial development (CSPV) during the 1972 to 2010 period was examined using the cointegration and vector error correction models for Granger causality tests. The main empirical results show that in the long term there is bidirectional causality between ENC and GDP, as well as a unidirectional causality going of ENC to CSPV. On the short term, only the variable ENC causes CSPV which demonstrates the interest to include this variable in the relation energy-growth. The research results strongly support the neoclassical perspective that energy consumption is not a limiting factor to economic growth in Tunisia. Accordingly, an important policy implication resulting from this analysis is that government can pursue the conservation energy policies that aim at curtailing energy use for environmental friendly development purposes without creating severe effects on economic growth. In future, the energy should be efficiently allocated into more productive sectors of the economy. Key words: Energy, financial development, growth, cointegration.