Miracle-dz/UniFAR-FTUs huggingface dataset:
Kinetic theory and rheology of dilute, nonhomogeneous polymer solutions

A phase‐space kinetic theory of dilute polymer solutions is developed to account for the effects of nonhomogeneous velocity and stress fields. The theory allows the configuration distribution function to depend on spatial location and explicitly treats the polymer molecule as an extended object in space. Constitutive equations for the mass flux vector and stress tensor are derived that predict polymer migration induced by stress gradients and nonuniform velocity gradients. In addition, the constitutive equation for stress contains a diffusive term in stress, and hence the model does not fall within the class of simple fluids. Simple shear flow between parallel plates is solved to illustrate the features of the constitutive equations. Asymptotic analysis and numerical calculations show the formation of boundary layers in stress, velocity gradient, and polymer concentration that arise near solid walls as a result of preferential orientation of the polymer molecules there. The thickness of these layers scale.
Rate-limited sorption of hydrophobic organic compounds by soils with well-characterized organic matter

This study is focused on the rate-limited sorption of homologous series of polycyclic aromatic hydrocarbons, alkylated benzenes, chlorinated benzenes, and chlorinated alkenes by two soils, one in which the organic matter is dominated by humic acid and the other by fulvic acid. The solutes sorbed more strongly to the humic-dominated soil than the fulvic-dominated soil. The first-order mo lecular connectivity index (1X v), a molecular solute descriptor, provided slightly better correlations with equilibrium sorp tion coefficients than did the octanol−water partition coefficient (Kow), an empirical solute descriptor. Thus, sorbate shape/structure may have a secondary influence on the overall magnitude of equilibrium sorption. However, sorbate shape/structure exhibited a significant influence on sorption kinetics. Distinct differences were observed in the correlations of mass-transfer coefficients to 1X v for the two soils. The differences were attributed to both sorbate shape/structure and the quantity (path.
Transport properties and equation of state of 1-bar eutectic melt in the system CaAl2Si2O8-CaMgSi2O6 by molecular dynamics simulation

Abstract Empirical potential molecular dynamics (EPMD) simulations of 1-bar eutectic composition liquid in the system CaAl2Si2O8-CaMgSi2O6 have been conducted using the interatomic pair-potential of Matsui (1998). Simulations using ~10 000 atoms over a wide range of conditions (r: 2200-5000 kg/m3; T: 1600-5500 K; P: 0-170 GPa) were used to derive an equation of state, determine self-diffusivities for all atoms, calculate melt viscosity, and investigate melt structures by coordination statistics. EOS results compare well to laboratory shock wave data up to ~25 GPa, diverging at higher pressure. Based on simulations of the end-member compositions of the join using the same potential, non-ideality in the volume of mixing at pressures below 10 GPa disappears at higher pressures. Ideal volume mixing at elevated pressure is consistent with inferences from laboratory shock wave studies of liquids in this system. The non-ideal volume of mixing at low pressure is directly correlated to structural differences between the end-member liquids and the mixing of cation-anion coordination polyhedra of differing volume. Self-diffusivities show reasonable agreement with laboratory values, with activation energies and activation volumes in the range 90-100 kJ/mol and 1-3 cm3/mol, respectively. Shear viscosities at 3500 K span from 1.8 × 10-3 Pa·s at low P to ~4.4 × 10-3 Pa·s at ~14 GPa.
Assessing objective and subjective factors of culinary career success: Exploring the influence of industry certifications

ABSTRACT Amidst a growing industry, foodservice professionals are seeking certifications to differentiate themselves from the competition. The American Culinary Federation (ACF) provides the most comprehensive culinary certification program in the United States, promoting professional development through specialized training in the culinary arts. Proponents of the ACF certification program boast benefits such as increased pay and prestige. However, there has been limited research focusing on the relationship between professional foodservice certifications and perceived career success. This study examined the relationships between culinary certifications and objective (i.e. salary) and subjective (i.e. job satisfaction, self-efficacy) indicators of career success.
THERMO-HYDRAULIC MODEL OF A TWIN-SCREW MULTIPHASE PUMP

The twin-screw multiphase pump has been studied as an alternative equipment to substitute the conventional system (fluid separation, liquid pumping and gas compression) in petroleum boosting. By “pumping” gas and liquid together, the multiphase pump could reduce production costs, particularly in deepwater activity. This paper presents a thermo-hydraulic model of a twin-screw multiphase pump developed to determine important parameters such as: volumetric efficiency, absorbed power, discharge conditions, heat transfer and pressure and temperature profiles. The continuous movement from suction to the discharge of pump chambers is divided in small discretive steps. This division allows the calculation of energy and mass balances for each screw chamber. At each step, it is possible to calculate mass and energy that enters and leaves one chamber. With this balance, pressure and temperature for the next step can be calculated. Differently from previous model, it considers not only water-air but also hydrocarbon mixtures (including petroleum heavy fractions) as working fluids. Besides, inclusion of screw rotation influence over peripheral backflow is not neglected as in previous models.Copyright © 2004 by ASME
Studies on the possibility of producing fats from food wastes by using micro-organisms. I: Factors affecting fat production from different Fungi

There is a great shortage of edible oils which must be compensated. Such shortage leads to the continuous research for alternative sources of edible oils which has therefore considerable national importance though little interest in exploiting micro-organisms for this purpose is evident. Factors affecting fat production from different fungi including incubation temperature, incubation period, pH-value, sugar concentration, spore count and carbon: nitrogen (C/N) ratio were studied. The optimum conditions enhancing the production of lipids from molasses media as food wastes by using Aspergillus niger, Aspergillus oryzae, Penicillium roqueforti and Rhizopus arrhizus were: 30,25,30 and 30° C for incubation temperature; 3, 7, 7 and 7 days for incubation period; 5,50:1; 7,70 :1;5,50: land 5,50 :1 for glucose percent and C/N ratio; 5,6,6 and 7 for pH-values and 2 × 104,1.5 × 104,2 × 104 and 1.3 × 105 for spore concentrations respectively. The oil contents of mycelium and fat coefficient obtained from the studied fungi grown in carrot wastes media were less than that resulted in molasses media. Untersuchungen uber eine mogliche Fettproduktion aus Lebensmittelnebenprodukten durch Mikroorganismen I: Faktoren, die die Fettproduktion verschiedener Pilze beeinflussen Wegen der geringen Mengen an esbaren Fetten, verglichen mit der Zunahme der Weltbevolkerung, mussen wissenschaftliche Untersuchungen zur Erforschung anderer Alternativquellen durchgefuhrt werden. Eine der wichtigen Quellen ist die Fettproduktion durch Mikroorganismen. Faktoren, die die Fettproduktion verschiedener Pilze beeinflussen, wie Inkubations-temperatur, -zeit, pH-Wert, Zuckerkonzentration, Keimzahl und C/N-Verhaltnis wurden in dieser Arbeit untersucht. Folgende optimalen Bedingungen fur die Fettproduktion aus Melassenahrboden als Lebensmittelnebenprodukt durch A. niger, A. oryzae, P. roqueforti und Rh. arrhizus wurden ermittelt: Inkubationstemperaturen von 30,25,30 und 30° C, Inkubationszeiten von 3,7,7 und 7 Tagen, Glucosegehalt in % und C/N-Verhaltnis von 5,50:1, 7,70:1,5,50 :1 und 5,50:1, pH-Werte von 5,6,6 und 7 und Keimzahlen von 2 × 104, 1.5 × 104, 2 × 104 und 1.3 × 105. Die Olkonzentration des Mycelium und der Fettkoeffizient der vier Pilze, die aus Mohrrubennahrboden stammen, sind geringer als die, die aus Melassenahrboden stammen.
Internal variable model for magneto-mechanical behaviour of ferromagnetic shape memory alloys Ni-Mn-Ga

In this paper, a predictive model of field-induced strain in Ferromagnetic Shape Memory Alloy (FSMA) is proposed. This phenomenological scalar magneto-mechanical model is built in the frame of thermodynamic of irreversible process. The strain mechanism corresponds to the reorientation process of twinned martensite platelets at constant temperature. In this model, physical microstructure parameters are chosen as variables: volume fraction z of one martensite variant and ratio a of magnetic domain width. Pure mechanical behaviour of FSMA is supposed to be decomposed in reversible (or anhysteretic) part and irreversible one. From dissipation, a yield function written in terms of energy, has been introduced to determine when reorientation of twinned martensite platelets (via internal variable z) could occur. Pure magnetic behaviour is supposed to be non-linear reversible. The coupling between magnetism and mechanics is introduced in the expression of magnetisation via microstructure parameters z and a. The good prediction capability of the proposed model is shown by an identification made on experiments performed by O'Handley & Murray: simulations of strain induced by pure mechanical loading or by applied magnetic field under constant compressive stress, are presented and compared with these experiments. These first results are very promising.
Ozonation of pine kraft lignin in alkaline solution. Part 1: Ozonation, characterization of kraft lignin and its ozonated preparations

Abstract Pine kraft lignin was purified to obtain a kraft lignin preparation (KL) with weight average molecular mass (Mw) of 5500. The KL was then ozonated with an ozone-air stream containing 2–2.5% of ozone in 0.1 M sodium hydroxide solution to prepare ozonated kraft lignin preparations with ozone consumption of 10, 25, 30 and 40% per KL; Oz-10-KL, Oz-25-KL, Oz-30-KL and Oz-40-KL, respectively. The pH of reaction mixture was decreased with increasing ozone consumption, while the carboxylic acid content and the Mw of resulting ozonated lignins increase with increasing ozone consumption. The KL and its ozonated preparations were then characterized by elemental composition, functional group analysis, molecular mass distribution and nitrobenzene-K4MnO4 oxidation. The results showed that the KL extensively undergoes oxidative cleavage of both side chains and aromatic moieties without decrease in the Mw as well as dehydrogenationive coupling of phenolic degraded fragments by active oxygen radical species, such as hydroperoxyl and hydroxyl radicals. The formation of these active oxygen radical species are produced by way of a series of reactions initiated by the reaction of ozone with hydroxide anions at pH range of 12.4–10.5, producing superoxide (-O2•) and hydroperoxyl (HOO•) radicals.
Balanced and adequate potassium and phosphorus nutrition of pasture

Abstract Pasture production responses from applications of four rates each of potassium (K) (0, 112.5, 225, 450 kg ha‐1) and phosphorus (P) (0, 60, 120, 240 kg ha‐1) in a factorial design were measured in a mowing trial with 60% of clippings returned at a K‐ and P‐responsive site (54.6 μg K ml‐1 and 9 μg Olsen P ml‐1) at Woodlands in Southland, New Zealand over 2 years. There were large significant responses in total pasture dry matter (DM) production to K and P. A bivariate Mitscherlich‐related equation accounted for 97% of the variation in measured values of total DM yield, 94–99% of the variation in ratios of K, P, and nitrogen (N) concentrations in mixed herbage, and 99–100% of the variation in nutrient ratios in white clover, summed or averaged over 2 years. The fitted equations were used to identify combinations of fertiliser P and K rates and ratios of K and P concentrations in mixed herbage and clover that resulted in balanced and adequate nutrition. Two nutrient elements are in balance when the yield response to one added on its own equals the response to the other added on its own, both in relation to the maximum yield. Balanced nutrition in total DM occurred at a K/P ratio of 5.1–7.4 for mixed herbage and 4.2–7.9 for clover, and were highest at higher rates of K and P. For balanced nutrition at 95% relative yield, K/P ratios were 6.8 for clover and 6.7 for mixed herbage. Fertiliser K/ (K + P) ratios for balanced nutrition increased from 0.5 for fertiliser expenditure of $50 ha‐1 to 0.7–0.8 for expenditure of $100–200 ha‐1. Modelled yield at the fertiliser K/(K + P) ratio for balanced nutrition in mixed herbage and clover DM was similar to maximum modelled yield. Mixed herbage and clover K/P ratios derived from economically optimal fertiliser K/P ratios were 6.2–6.6 and 5.6–6.7, respectively. Using N concentration as an internal standard, nutrient adequacy is defined as the herbage yield with K and P in physiological balance relative to the maximum yield with K and P in physiological balance and expressed as RY [KP]. At 95% RY [KP], adequate nutrition was achieved at K/N of 0.77 for mixed herbage and 0.46 for clover. Overall, the results from the trial reported here confirm that ratios of nutrient concentrations are useful indicators of balanced and adequate K and P nutrition for total pasture production. Mixed herbage or clover nutrient concentrations and ratios were both effective indicators of balanced and adequate nutrition.
The Influence of Molar Substitution on the Water Binding Capacity of Hydroxypropyl Maize Starches

Hydroxypropyl maize starches of molar substitution ranging from 0–0.27 were prepared and their water binding capacities determined using differential scanning calorimetry. Water binding capacity decreased initially from 0.39 g water/g dry unmodified maize starch to 0.36 g water/g dry starch of molar substitution 0.07. Further increases in molar substitution caused water binding capacity to increase to 0.45 g water/g dry starch of molar substitution 0.27. Der Einflus der molaren Substitution auf das Wasserbindungsvermogen von Hydroxypropyl-Maisstarken. Hydroxypropyl-Maisstarken mit molarer Substitution zwischen 0 und 0,27 wurden dargestellt und ihr Wasserbindungsvermogen unter Anwendung der Differential-Raster-Kalorimetrie bestimmt. Das Wasserbindungsvermogen verringerte sich anfanglich von 0,39 g Wasser/g trockene nicht modifizierte Maisstarke auf 0,36 g Wasser/g trockene Starke mit einer molaren Substitution von 0,07. Der weitere Anstieg der molaren Substitution verursachte das Ansteigen des Wasserbindungsvermogens auf 0,45 g Wasser/g trockene Starke mit einer molaren Substitution von 0,27.
Characterization of Styrene Copolymers Using Size-Exclusion Chromatography with On-line FT-IR Viscometer Detectors

Abstract Size-exclusion chromatography (SEC) provides a rapid method for determining molar mass distributions of macromolecules. In this article, we demonstrate the method of SEC coupled with an on-line Fourier-transform infrared (FT-IR) detector and an on-line differential viscometer developed for copolymer characterization. Using a chemometric technique to analyze the FT-IR spectra allows for determining copolymer concentration and composition. The combination of the FT-IR concentration detector and the viscometer allows the universal calibration method to be used for measuring copolymer molar mass. Molar mass distribution and compositional distribution are described and the method's application demonstrated using several types of styrene copolymers.
Kinetics and mechanism of the oxidation of thiosulphate ions by copper(II) ions in aqueous ammonia solution

Copper(II) ions in aqueous ammonia solution oxidize thiosulphate ions initially to tetrathionate ions; the latter then undergo a subsequent disproportionation reaction to yield trithionate and thiosulphate ions. The detailed kinetics of the reaction suggest a mechanism which involves substitution of thiosulphate ion into the co-ordination sphere of a triamminecopper(II) complex in the rate-determining step. A one-equivalent electron transfer from the thiosulphate to the copper(II) ion, occurring in the intermediate triamminecopper(II)–thiosulphate complex, gives rise to copper(I) and S2O3– ions, the latter dimerizing to tetrathionate ions.
Bisadducts of C70 as Electron Acceptors for Bulk Heterojunction Solar Cells: A Theoretical Study

In the present study, we have used density functional molecular orbital calculations to investigate the energy levels of the frontier orbitals of novel bisadducts of Phenyl-C71-Butyric-Acid-Methyl Ester (bis[70]PCBM) in an attempt to verify if they can be used as electron acceptor in polymer-fullerene solar cells. C70 derivatives are promising materials for these devices because they have a stronger and broader absorption compared to C60 ones, and they can improve the current output of the corresponding polymer-fullerene solar cells. The calculated LUMO levels for the bis[70]PCBM isomers are higher compared to the monoadduct already used as acceptor in such devices. Since the open circuit voltage (Voc) for devices with ohmic contacts is proportional to the difference between the HOMO of the donor polymer and the LUMO of the acceptor, these bisadducts can increase the Voc of polymer solar cells having poly(3-hexylthiophene) as donor.
Renewable Agricultural Fibers as Reinforcing Fillers in Plastics: Mechanical Properties of Kenaf Fiber-Polypropylene Composites

Kenaf (Hibiscus Cannabinus) is a fast growing annual growth plant that is harvested for its bast fibers. These fibers have excellent specific properties and have potential to be outstanding reinforcing fillers in plastics. In our experiments, the fibers and polypropylene (PP) were blended in a thermokinetic mixer and then injection molded, with the fiber weight fractions varying to 60%. A maleated polypropylene was used to improve the interaction and adhesion between the non-polar matrix and the polar lignocellulosic fibers. The specific tensile and flexural moduli of a 50 % by volume (39 % by volume) of kenaf-PP composites compares favorably with a 40 % by weight of glass fiber-PP injection molded composites, These results suggest that kenaf fibers are a viable alternative to inorganic/mineral based reinforcing fibers as long as the right processing conditions are used and for applications where the higher water absorption is not critical.
Practical selection of elastomer materials for vacuum seals

Proper selection of polymer seal materials must consider restraints imposed by the application and the properties of available materials. Data and concepts presented enable the working vacuum technician to make an educated selection considering chemical and mechanical properties, outgassing, permeation, and nuclear radiation damage. Early reports on the new perfluoroelastomer Kalrez have shown problems with compression set and adhesion, but these difficulties may have resulted from improper groove design.
Effect of Different Starches on Colors and Textural Properties of Surimi-Starch Gels

The effect of starches on textural properties and colors of surimi-starch gels were investigated by measuring texture profile analysis parameters, penetration force, gel strength, and color values. Surimi-starch gels, with potato native starch, showed higher hardness, chewiness, whiteness, and gel strength compared with those with corn starch. Potato native starch AP1500 and its modified starches, including acetate esterified starch STABI-AP0170, cross-linked and esterified starch DURA-MIP0075, improved textural properties and whiteness of surimi-starch gels significantly, whereas potato oxidized starch Flu-XP0450 weakened surimi-starch gel forming ability. AP1500, STABI-AP0170, and DURA-MIP0075 were suitable to be added into surimi-based product to improve product quality.
Synthesis and characterization of lead-free ternary component BST–BCT–BZT ceramic capacitors

Polycrystalline sample of lead-free 1/3(Ba0.70Sr0.30TiO3) + 1/3(Ba0.70Ca0.30TiO3) + 1/3(BaZr0.20Ti0.80O3)(BST-BCT-BZT) ceramic was synthesized by solid state reaction method. Phase purity and crystal structure of as-synthesized materials was confirmed by X-ray diffraction (XRD). Temperature-dependent dielectric permittivity studies demonstrated frequency-independent behavior, indicating that the studied sample has typical diffuse phase transition behavior with partial thermal hysteresis. A ferroelectric phase transition between cubic and tetragonal phase was noticed near room temperature (~ 330 K). Bulk P–E hysteresis loop showed a saturation polarization of 20.4 μC/cm2 and a coercive field of ~ 12.78 kV/cm at a maximum electric field of ~ 115 kV/cm. High dielectric constant (e ~ 5773), low dielectric loss (tan δ ~ 0.03) were recorded at room temperature. Discharge energy density of 0.44 J/cm3 and charge energy density of 1.40 J/cm3 were calculated from nonlinear ferroelectric hysteresis loop at maximum electric field. Dielectric constant at variable temperatures and electric fields, ferroelectric to paraelectric phase transition and energy storage properties were thoroughly discussed.
Highly controlled synthesis of poly(N-vinylpyrrolidone) and its block copolymers by organostibine-mediated living radical polymerization

Poly(N-vinylpyrrolidone)s (PNVPs) with well-defined macromolecular structure were prepared by organostibine-mediated living radical polymerization. PNVPs with expected number-average molecular weight (Mn = 3000−84 000) and low polydispersity indexes (PDIs = 1.1−1.3) were formed by heating a solution of organostibine mediator and NVP in the presence of AIBN at 60 °C. The polymer structure was analyzed by matrix-assisted laser desorption/ionization time-of-flight (MALDI TOF) mass and 2H NMR spectroscopies after reduction of the organostibanyl polymer end by tributyltin deuteride. The analyses reveal that, while the addition of AIBN considerably enhances the rate of the polymerization, the effect of azobis(isobutyronitrile) (AIBN)-derived radical to the ω-end structure is negligible. The analyses also reveal the existence of “dead” dormant species due to head-to-head addition followed by the organostibanyl group transfer. However, since the probability of the head-to-head addition is small (0.02−0.10%) compa.
Developing environmentally benign and effective organic wood preservatives by understanding the biocidal and non-biocidal properties of extractives in naturally durable heartwood

Abstract Wood products for exterior residential applications have long been protected with metallic preservatives. However, environmental and disposal concerns and governmental regulations have resulted in a growing trend to employ organic systems based on relatively benign and expensive agrochemicals. To develop organic preservatives that have increased efficacy and lower cost, various groups are studying the biocidal and non-biocidal properties of extractives present in naturally durable heartwoods. In this study, we determined the fungicidal, free radical scavenger/antioxidant, metal chelation and Fe3+ reducing properties of some flavones and flavonoid analogs and chromones. The results support our earlier hypothesis that the abiotic antioxidant, Fe3+ reduction and subsequent metal complexation properties, in combination with the extractives’ fungicidal properties, all have a role in natural durability. Consequently, it may be possible to employ non-biocidal additive(s) with the above abiotic properties to enhance the efficacy of the relatively expensive organic agrochemicals used to protect wood.